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US 4,360,975 AGranted
Perspective drawing machine
OwnerFrank R. Wurtzinventor
Life of this patent
Estimating the term…
Abstract
This invention relates to a perspective drawing machine and more particularly, to a machine which will keep track of a chosen vanishing point. Two machines are disclosed; one, a mechanical machine works to .+-.22.5 degrees with an error of .+-.4.7%. The second is an electronic machine that corrects for the above error and can have a much wider range. Both machines convert instantly from the left hand vanishing point to the right hand vanishing point and then to a standard drafting machine when required.
Claims17
A mechanical perspective drawing machine comprising the combination of:
- a linear gear running the length or width of a drawing table;
- a follower gear riding on said linear gear to give an indication of a change from a chosen position;
- a case to hold said perspective drawing machine;
- means to mount said case above said linear gear and to move said case between one chosen position to another chosen position;
- an input shaft connected solidly to said follower gear and running upwardly to and through bearings in the bottom of said case, through said case and into and through bearings in the top of said case;
- a shaft coupler mounted solidly to said input shaft between the top of said case and the bottom of said case;
- an RVP (right vanishing point) input gear below said shaft coupler and riding loosly on said shaft;
- an LVP (left vanishing point) input gear above said shaft coupler and riding loosly on said shaft;
- a rule control frame;
- an output shaft running through a bearing in the bottom of said case upwardly through said case to and through a bearing in the top of said case continuing upward to and through a bearing in said rule control frame;
- a drafting rule coupler, having a first part which is between said bottom of said case and said top of said case and a second part which is between said top of said case and said rule control frame, both parts of said drafting rule coupler being solidly connected to said output shaft;
- a drafting rule connects to said drafting rule coupler by standard means;
- an RVP output gear below said first part of said drafting rule coupler and riding loosly on said output shaft;
- an LVP output gear above said first part of said drafting rule coupler and riding loosly on said output shaft;
- means to connect said input gears to said shaft coupler and said output gears to said first part of said drafting rule coupler and said second part of said drafting rule coupler to said rule control frame when needed;
- means to couple said RVP input gear to said RVP output gear with a pre-calculated ratio and to couple said LVP input gear to said LVP output gear with a precalculated ratio
- a drafting rule control knob connected to said output shaft outside of said rule control frame;
- means to drive said input shaft;
- means to lift said drafting rule off a drawing when changing said drafting rule position;
- and
- means to secure said shafts vertical position.
18 more elements
An electronic perspective drawing machine comprising:
- a linear gear running the length or width of a drawing table;
- a follower gear riding on said linear gear to indicate a change from a chosen position;
- a case to hold said perspective drawing machine;
- means to mount said case above said linear gear and to move said case between one chosen position to another chosen position;
- an input shaft connected soldily to said follower gear and running upwardly to and through a bearing in the bottom of said case, through said case and into and through a bearing in the top of said case;
- a drive gear mounted on said input shaft between the bottom of said case and the top of said case;
- an RVP input gear mating with one side of said drive gear;
- an LVP input gear mating with the opposite side of said drive gear:
- an output shaft passing through said case downwardly through a drafting rule coupler, connected lightly to said output shaft;
- a drafting rule connects to said drafting rule coupler by standard means;
- means to produce a voltage potential proportional to the change of position of said case for both said RVP and said LVP;
- means to produce a multiplier voltage potential for both said RVP and said LVP;
- means to produce a voltage potential proportional to a circular movement of said drafting rule from a zero reference potential at an eye level position;
- means to lift said drafting rule off a drawing when changing said drafting rule position;
- means to compute a correction voltage potential, equal to said voltage potential proportional to the change of position of said case multiplied by said multiplier voltage potential for both said RVP and said LVP;
- means to compare said correction voltage potential and said voltage potential proportional to said circular movement of said drafting rule and to give a zero reading when the above compared voltage potentials are equal;
- means to drive said input shaft;
- and
- means to move said drafting rule in said circular movement until said compared voltage potential is zero.
16 more elements
Dependencies are inferred from the claim text.