Graphics instrument

专利名称：Graphics instrument发明人：Sarah Hesse,Justin J. Shapiro申请号：US05/598781申请日：19750724公开号：US04004347A公开日：19770125

摘要：A graphics instrument is disclosed for use in drawing and measuring. Theinstrument includes a pair of coplanar scale members mounted for concentric mutualrotation. A circular graduated scale on the outer member displays angular degree andradian values, and this scale is in register with a circular graduated scale on the innermember which displays both angular and trigonometric function values. Straight edgesare formed to extend along axes of each scale member to facilitate measurement anddrawing by a marking instrument. In one embodiment the outer member defines apolygon configuration which provides a straight edge, and the straight edge of the innermember extends along a diameter of the latter. In another embodiment the two

members are annular and carry radially extending arms which define straight edges uponwhich graduated linear measurement scales are marked. The inner member is formedwith a central opening into which extensions of the two arms project. The inner terminalends of the arm extensions meet at the center of the two scale members to facilitatedrawing the vertex of an angle. The arms may be releasably locked in any selectedposition about the scale members by means of the eccentric cam locks and the arms maybe assembled in inverse position to function as a T-square. A sliding indicator may bemoved to a selected position along one arm to facilitate drawing an arc with any radius

along the arm while simultaneously measuring the radius and value of the arc which isdrawn.

申请人：HESSE; SARAH,SHAPIRO; JUSTIN J.

代理机构：Flehr, Hohbach, Test, Albritton & Herbert

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