Parallel and perspective drawing device with angular setting means

Claim 2

A parallel drawing device comprising base means having a first pivot means, a first arm having ends and pivotally mounted at one end thereof on the first pivot means, a second arm having ends and an arm axis, a second pivot means pivotally mounting one end of the second arm to the other end of the first arm, a third arm having ends, a third pivot means mounting one end of the third arm to the other end of the second arm, a fourth pivot means secured to the other end of the third arm and having a vertical axis, a arm-connecting means connecting the base means with the third arm to retain the relative angular position of this arm with respect to the base means in all positions of the first and second arm, a ruling edge member having at least one ruling edge, mounting means for the ruling edge member pivotally mounting the ruling edge member on the fourth pivot means, the ruling edge being in alignment with the axis of the fourth pivot means, an indexing member secured to the fourth pivot means and having a plurality of indexing means angularly spaced uniformly over at least 180* thereof, and a connecting member carried by the ruling edge mounting means having a neutral position and a position connecting the ruling edge mounting means with one of the indexing means on the indexing member.

Claim 3

A parallel drawing device as in claim 1 for right-hand and left-hand mounting of the device on the drawing board in which the indexing means extends over 360* of the indexing member, and means to adjust one of the parts including the base and the arm connecting means through 180*.

Claim 4

A parallel drawing device as in claim 1 including a protractor secured to the fourth pivot means, means carried by the ruling edge mounting means to adjust the angular position of the ruling edge mounting means with respect to the protractor with the connecting member in neutral position, and means to clamp the ruling edge mounting means in adjusted position.

Claim 5

A perspective and parallel drawing device as in claim 1 including a control rod, control rod pivot means pivotally mounting said rod on the fourth pivot means, a perspective frame secured to the other end of the second arm and extending at right angles to its arm axis, control pivot means mounted on the perspective frame including a control pivot slidably receiving the control rod and having its center at right angles to the center axis of the third pivot means, conversion means to convert the device to and from a perspective drawing device and a parallel drawing device including said connecting member being operable to a third position to selectively connect the ruling edge mounting means with the control rod pivot means.

Claim 6

A perspective and parallel drawing device as in claim 4 including a perspective scale carried by the perspective frame, and adjusting means carried by the control pivot means to adjust the same along the perspective scale and retaining the center of the control pivot means at right angles to the center axis of the third pivot means in all adjusted positions.

Claim 7

A perspective and parallel drawing device as in claim 5 in which the conversion means has a pivot to pivotally mount the same on the ruling edge mounting means, interlocking means on the conversion means such that pivoting of the latter in one direction interlocks the same with an indexing means and pivoting in the opposite direction interlocks the conversion means with the control rod pivot means.

Claim 8

A perspective and parallel drawing device as in claim 6 in which the indexing means are notches, the interlock connection on the control rod pivot means has at least one notch, and the conversion means has an interlock pin on one side of its pivot for interlocking with a notch of the indexing means and has an interlock pin on the other side of its pivot to interlock with a notch on the control rod pivot means.

Claim 9

A perspective and parallel drawing device as in claim 7 in which the indexing notches are tapered outwardly for a tight engagement of the connecting pin therein.

Claim 10

A perspective and parallel drawing device as in claim 8 in which the conversion means has a radially tapered notch to tightly receive the conversion means pivot on the ruling edge mounting means, and spring means connected with the conversion means to press the same radially inwardly.

Claim 11

A perspective and parallel drawing device as in claim 7 in which the conversion means has a radially tapered notch to tightly receive the conversion means pivot on the ruling edge mounting means, and spring means connected with the conversion means to press the same radially inwardly.

Claim 12

A perspective and parallel drawing device as in claim 6 in which the indexing means are holes, the interlocking connection on the control rod pivot means is at least one hole, the conversion means being mounted on the straight edge mounting means for vertical upward and downward movement from a neutral position, and having an upwardly projecting pin and a downwardly projecting pin, and conversion operating means connected with the conversion means to selectively move the same vertically into interlocking connection with an indexing means and with the control rod pivot means.

Claim 13

A perspective and parallel drawing device as in claim 11 in which the conversion operating means includes a conversion means operating member pivotally mounted on the ruling edge mounting means and having a cam on the periphery thereof engaging the conversion member to move the same vertically upon pivotal movement of the conversion means operating member.

Claim 14

A perspective and parallel drawing device as in claim 4 including a worm gear secured to the indexing disc, a worm for engagement with the worm gear, worm mounting means carried by the ruling edge mounting means mounting the worm for engagement with and disengagement from the worm gear and a protractor scale carried by the fourth pivot means.

Claim 15

A perspective and parallel drawing device as in claim 6 including a worm gear secured to the indexing disc, a worm for engagement with the worm gear, worm mounting means carried by the ruling edge mounting means mounting the worm for engagement and disengagement from the worm gear, and a protractor scale Carried by the fourth pivot means.

Claim 16

A perspective and parallel drawing device as in claim 13 including a verner scale carried by the casing and positioned in cooperative relation with the protractor scale.

Claim 17

A perspective and parallel drawing device as in claim 5 in which the ruling edge mounting means receives the ruling edge member to selectively project from opposite sides thereof, the indexing means being provided through 360* of the indexing member and the control rod pivot means having two interlocking means spaced 180* apart.

Claim 18

A perspective and parallel drawing device as in claim 16 in which the ruling edge mounting means is a guideway open at both ends thereof, the end of the ruling edge member having a stem received in the guideway from either end thereof, and the opposite ruling edge being in line with the axis of the fourth pivot when the ruling edge member projects in a left-hand direction.

Claim 19

A perspective and parallel drawing device as in claim 1 in which the arm connecting means includes a first pulley, a second pulley, a third pulley secured to the second pulley, and a fourth pulley, means to secure the first pulley to the base means, means rotatably mounting the second and third pulleys on the second pivot means, means pivotally mounting the fourth pulley on the third pivot means, the third arm being secured to the fourth pulley, band means connecting the first and second pulleys, band means connecting the third and fourth pulleys, and the diameters of the first and second pulleys and the diameters of the third and fourth pulley being directly proportional to the length of the first and second arms respectively between the axes of their respective pivot means.

Claim 20

A perspective and parallel drawing device as in claim 5 including a detent carried by the base means or the first arm and a locating means carried by the other part which locating means is to be engaged by the detent.

Claim 21

A perspective and parallel drawing device as in claim 19 including adjusting means for one of the parts including the detent or the locating means to adjust the same circumferentially with respect to the other part.

Claim 22

A perspective and parallel drawing device as in claim 20 including actuating means carried by the part having the detent to engage the detent to disengage the same from the locating means and to retain the detent disengaged therefrom.

Claim 23

A perspective drawing device comprising base means having a first pivot means having a vertical axis, arm means mounted on the first pivot means, including a first perspective arm having ends and an arm axis, a second pivot means pivotally mounting one end of the first perspective arm to the first pivot and having a vertical axis, a second perspective arm having ends, a third pivot means mounting one end of the second perspective arm to the other end of the first perspective arm and having a vertical axis, a fourth pivot means secured to the other end of the second perspective arm and having a vertical axis, arm connecting means connecting the base means with the second perspective arm to retain the relative angular position of this arm with respect to the base means in all positions of the said first and said second arms including at least one belt, a ruling edge member having at least one ruling edge mounting means for the ruling edge member pivotally mounting the ruling edge member on the fourth pivot means, the ruling edge being in alignment with the axis of the fourth pivot means, a control rod, control rod pivot means pivotally mounting said rod on the fourth pivot means, a perspective frame secured to the other end of the second arm and extending at right angles to its arm axis, control pivot means mounted on the perspective frame including a control pivot slidably receiving the control rod and having its center at right angles to the center axis of the third pivot means, adjusting means for the second arm to lengthen and shorten the same, and adjusting means for the thIrd arm to shorten and lengthen the same.

Claim 24

A perspective drawing device comprising base means having a first pivot means having a vertical axis, arm means mounted on the first pivot means, including a first perspective arm having ends and an arm axis, a second pivot means pivotally mounting one end of the first perspective arm to the first pivot and having a vertical axis, a second perspective arm having ends, a third pivot means mounting one end of the second perspective arm to the other end of the first perspective arm and having a vertical axis, a fourth pivot means secured to the other end of the second perspective arm and having a vertical axis, arm connecting means connecting the base means with the second perspective arm to retain the relative angular position of this arm with respect to the base means in all positions of the said first and said second arms including at least one belt, a ruling edge member having at least one ruling edge mounting means for the ruling edge member pivotally mounting the ruling edge member on the fourth pivot means, the ruling edge being in alignment with the axis of the fourth pivot means, a control rod, control rod pivot means pivotally mounting said rod on the fourth pivot means, a perspective frame secured to the other end of the second arm and extending at right angles to its arm axis, control pivot means mounted on the perspective frame including a control pivot slidably receiving the control rod and having its center at right angles to the center axis of the third pivot means, adjusting means for the second arm to lengthen and shorten the same, and adjusting means for the thIrd arm to shorten and lengthen the same.

Claim 25

A perspective and parallel drawing device as in claim 4 including adjusting means for the second arm to lengthen and shorten the same, and adjusting means for the third arm to shorten and lengthen the same.