Instrument for making perspective drawing
OwnerKazuomi Ohtakeinventor
Life of this patent
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Abstract
An instrument adapted for making perspective drawing, comprising a slider on a base plate and a link pivoted to two levers of exactly equal lengths between pivot centers and at equal distances on the slider and the link. The arrangement further includes a ruler or bar extending in a direction generally transversely to the levers and connected thereto by means of a joint structure which is slidable along the levers to any desired set position and which permits a rotational as well as a sliding motion of the ruler relative to the joint center as the angular position of the ruler relative to the levers is changed.
Claims3
An instrument for making perspective drawings comprising a base plate to be located on a drawing board, a slider, means mounting said slider on said base plate for rectilinear sliding movement thereon, means for clamping said slider to said base plate in any desired position therealong, a parallelogram lever-and-link arrangement comprising a pair of parallel levers pivotally mounted at one end thereof on said slider and a link extending between and pivotally connected to the opposite ends of said levers, a ruler, and a pair of joint structures respectively interconnecting said ruler with said levers, each said joint structure including a sleeve establishing a sliding fit on said lever together with means for releasably fastening them together, a bracket pivotally mounted on said sleeve, and shoe means carried by said bracket, said ruler being provided with a longitudinally extending slotted portion with which said shoe means are engaged for slidingly guiding longitudinal movement of said ruler, and means for clamping said shoe means to said slotted portion at any desired position along said ruler.
Dependencies are inferred from the claim text.