US 3323214 A
Abstract available in
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Description (OCR text may contain errors)
June 6, 1967 M. sAcHs-ENHAUS ETAL 3,323,214
ELLIPSOGRAPH Filed oct. .31, 196e '5 sheetsheet 1 Jlm 6, 1967 M. sAcHsENHAus ETAL 3,323,214
r V' ELLIPSOGRAPH Filed Oct. 51, 1966 5 Sheets-Sheet 2 Vrin/rales rrys.
June 6, 1967 M. sAcHsl-:NHAUS ETAL 3,323,214
ELLIPSOGRAPH I Filed Oct. 31, 1966 5 Sheets-Sheet /M/fA/mes dyrwy, r
United States Patent O 3,323,214 ELLIPSOGRAPH Marcel Sachseuhaus, 54 Ave. de Stalingrad, Fontenaysous-Bois, and Pierre Cribier, 3 Square Servan, Paris, France Filed Oct. 31, 1966, Ser. No. 590,99() Claims priority, application France, Nov. 5, 1965,
s claims. tcl. .as- 31) The present invention relates to an ellipsograph of the kind comprising `a base adapted to be placed on a iiat working surface, two slides at right angles to each other carried at different levels on the base parallel to the said working surface, a rod sliding in each of the said slides and an operating unit comprising an operating crankhandle, the shaft of which is pivotally mounted on one of the sliding rods, a rst so-called operating rule keyed on the shaft of the said crank-handle, a guide adjustable in position along the said operating rule and pivotally mounted on the other sliding rod, a second so-called drawing rule keyed on the said guide and `a tracing tool adjustably mounted in position along the said drawing rule.
The present invention has for its object improvements in an ellipsograph `of this kind, having the particular purpose of improving its accuracy, its operation and its utilization.
In accordance with one of these improvements, the operating unit is movably mounted perpendicularly to the work surface against the action of an elastic restoring means which urges the said unit in a direction such that, when at rest, the tracing tool is not in contact with the work surface.
It has already been proposed to suspend the tracing tool elastically in such manner that this latter is continuously applied against the work surface in order to absorb any possible surface irregularities of this latter. In the present invention, it is the `operating unit which is Wholly suspended elastically, in combination with a guiding perpendicular to the work surface, so that it is possible to obtain a delicate and accurate touch on the work surface by the tracing tool, which is removed from the said work surface in the position of rest; in addition, this arrangement advantageously permits the drawing of broken lines.
In accordance with another improvement of the invention, the drawing rule is keyed on the guide so as to be able to be adjusted angularly in position with respect to this latter, that is to say, ultimately with respect to the operating rule. This arrangement advantageously permits the drawing of identical and concentric ellipses, the axes of which have pivoted as a Whole about their common centre.
Other improvements and their advantages will also be brought out during the course of the description which follows below of one form of embodiment shown by way of example and without limitation, reference being made to the accompanying drawings, in which:
FIG. l is a perspective view of an ellipsograph provided with the improvements according to the invention;
FIG. 2 is a view in partial cross-section of this ellips-ograph, passing through the shaft of the operating crankarm;
FIG. 3 is a diagrammatic view from below of an alternative form of construction of the base of the ellipsograph in accordance with the invention;
FIG. 4 is a partial view in cross-section of this alternative, taken along the line lV-IV of FIG. 3;
FIG. 5 is a partial view looking from below of an alternative form of construction of a slide of the ellipsograph according to the invention;
FIG. 6 is a partial section of this alternative, taken along the line VI-VI of FIG. 5;
FIG. 7 is a partial view similar to FIG. l, and concerns a further improvement.
In accordance with the form of embodiment chosen and shown in FIGS. l and 2, the ellipsograph according to the invention comprises a base 1 having the form of a square, the arms of which each carry at their free extremity a slide 11 mounted overhung. The slides 11 are located at different levels with respect to the work surface 13. In its angle zone, the base 10 is weighted by a counter-weight 12. The arms of the base 10 are extended in contact with the work surface 13 by lugs 14, each pierced with a housing 15 permitting the arrangement of a retractable pin 16 for anchoring the base 10 on the work surface.
A rod or bar 17 slides in each of the slides 11; the upper rod 17 carries at its extremity a socket with balls 18, which is described later, in which is rotatably and slidably mounted the shaft 19 of an operating crankarm 20. Between the socket 18 and the arm 21 of the crank-arm 20 is interposed a helicoidal spring 22 arranged coaxially round the shaft 19.
At the lower extremity of the shaft 19 of the crank-arm 20 is keyed a so`called operating rule 23, adapted to slide in a guide 24 which is slidably engaged on the rule 23 and can be locked in position along this rule by tightening a screw 25. The guide 24 has a shaft. 26 rotatably and slidably mounted in a socket with balls 27, carried at the extremity of the lower rod 17.
At the lower extremity of the shaft 26 of the guide 24 is arranged a so-called drawing rule 28 mounted with angular adjustment in position with respect to the shaft 26 by the action of a clamping screw 29. On the drawing rule 28 is slidably mounted a tracing tool 36; this tracing tool can be locked in position along the rule 28 by the action of a clamping screw 30.
The ball socket 18, shown in detail in FIG. 2, has the purpose of ensuring a strictly vertical guiding of the shaft 19 which passes through it. To this end, it comprises two rings of balls 31 and 32. The rings 31 and 32 are each associated with an annular cage 33 and 34 respectively, and their balls are arranged in contact -on the one hand with the socket 13 and on the other hand with the shaft 19 which passes through this latter. In. addition, according to the invention, a helicoidal spring 235 arranged in the socket 18 and at the base of this latter, prevents the locking of the balls of the lower ring 32 when the latter reaches the end of its downward travel. The socket 27 with balls is similar t-o the socket 18.
In the position of rest, as shown in FIG. 2, the spring 22 urges upwards the operating unit formed conjointly by the operating crank-arm 20, the rule 23, the guide 257 the rule 28 and the tool 36. Thus, in the position of rest, the tool 36 is not in contact with the work surface 13. The utilization of the apparatus according to the invention is effected by adjustment of the positions of the guide 25 on the rule 23 and of the tool 36 on the rule 28, as a function of the desired characteristics of the ellipse to be drawn.
The drawing rule 28 is normally arranged along the plane which contains the operating rule 23 and the shaft 26; the axes of the ellipses drawn then correspond to the orthogonal projections of the sliding rods 17 on the work surface. By acting on the screw 29, the drawing rule 28 can be brought to make an angle with the operating rule 23. The axes of the ellipses drawn are then displaced angularly as a whole by an equal angle with respect to the axes previously defined, by rotation about their common centre.
It will be noted that, according to the invention, the overhang of the slides 11 leaves advantageously free the work face, which permits the drawing of ellipses of large size, and that the elastic suspension of the operating assembly in combination with a guiding action on this latter perpendicular to the work surface, makes it possible to obtain a delicate and accurate touch of the tracing tool on the work surface.
In accordance with the alternative form shown diagrammatically in the underside view of FIG. 3 and the cross-section shown in FIG. 4, the base is provided with three cylindrical feet 40, the apparent contour of which slightly projects beyond the apparent contour of the base. The central foot 40, that is to say that which is located in the angle zone of the base 10, is adjustably mounted in Iposition with respect to the base 10, in the direction of the arrows 41, so as to permit the planes 42A and 42B tangential to the feet 41 form a perfectly straight dihedron. The central foot is then locked finally in this position.
This arrangement makes it possible to avoid accurate machining of the faces of the lug 14 which are intended to bear against a work square.
In accordance with the form of embodiment shown in FIGS. 5 and 6, each of the slides associated with a sliding rod 17 is formed by three bearing rollers 45, 46 and 47. The rollers 45 and 46 are arranged on the same side of the rod 17, and the roller 47 is arranged on the other side of this same rod, in a central position with respect to the rollers 45 and 46. Each of the rollers 45, 46 and 47 is provided with a machined external rolling strip in s-uch manner as to have two conical bearing surfaces forming between them an angle 120, and conjointly, the rod 17 is provided laterally with two grooves 48, 49 in the form of a V.
Each roller is carried by a shaft 50 fixed by a bolt 51 to the base 10.
The bolt 51 associated with the roller 47 passes eccentrically through the corresponding shaft 50, and conjointly, this shaft 50 is provided externally with two small holes 52 enabling it to be rotated.
This arrangement permits a dynamometric adjustment of the pressure of the roller 47 on the rod 17, by causing the shaft 50 to rotate with respect to the bolt by which it is carried.
Thus, as shown in FIG. 7, the operating rule 23 is provided alternatively at its extremity with a stop-screw 123. When the guide 24 which slides on the rule 23 comes into abutment against the screw 123, the shaft 26 carried by this guide is located in the exact extension of the shaft 19 of the operating crank-arm. In such a case, the ellipsograph obviously draws circles.
What we claim is:
1. An ellipsograph of the kind comprising a base adapted to be placed on a flat working surface, two slides at right angles to each other, said slides being mounted at different levels on said base parallel to said working surface, a rod sliding in each of said slides, and an operating assembly including an operating crank-handle having a shaft pivotally and slidably mounted on one of said sliding rods, a first operating rule keyed on the shaft of said crank-handle, a guide adjustable in position along said operating rule and pivotally and slidably mounted by a shaft on the other sliding rod, a second drawing rule keyed on said latter shaft, a tracing tool adjustably mounted in position along said drawing rule, at least said tracing tool being movably mounted perpendicularly to the working surface, and elastic restoring means which urges at least the tracing tool in such a direction that, when at rest, the tracing tool is not in contact with said working surface.
2. An elli-psograph as claimed in claim 1, in which said elastic restoring means comprises a helicoidal restoring spring arranged coaxially around said first-named shaft.
3. An ellipsograph as claimed in claim 1, in which said drawing rule is keyed on said guide in such manner as to be capable of being adjusted angularly in position with respect to said guide, that is to say with respect to said operating r-ule.
4. An ellipsograph as claimed in claim 1, in which said two slides are mounted overhung on said base.
5. An ellipsograph as claimed in claim 1, in which said base is loaded with a counter-weight opposite to said slides.
6. An ellipsograph as claimed in claim 1, in which said base is supported on said working surface by cylindrical feet, the apparent contour of said feet projecting beyond the apparent contour of said base, the central foot being adjustably mounted in position on said base parallel to said working surface.
7. An ellipsograph as claimed in claim 1, in which each said slide is constituted by three rollers, each rotatably mounted with bearings on a shaft carried Iby said base, two of said rollers being disposed on the same side with respect to the associated sliding rod, while the other roller is arranged on the iother side of said sliding rod, the shaft of said latter roller being Xed to said base by a bolt which passes eccentrically through said shaft.
8. An ellipsograph as claimed in claim 1, in which said operating rule comprises an abutment means mounted in such manner as to stop the guide which it carries level with the shaft of said operating crank-handle.
No references cited.
LEONARD FOREMAN, Primary Examiner.