pantograph

Pluralpantographs

Formspantographs, pantographing, pantographed

1. 1
   nouncountable

   A jointed framework of bars arranged in parallelograms that links two pointers so they move together, used especially to copy a drawing at a larger or smaller scale.

   Draftsmen once relied on a pantograph to scale technical drawings up for display.

   She clamped the pantograph to the board and traced the original to produce an enlarged copy.

   Similaromnigraph

   Note

   The original instrument that the other uses grew from. French pantographe joins Greek words for "all" and "write": a device that could copy anything drawn. Moving one point drives a second along a parallel path, so the copy can be exact or scaled. The ratio depends on where the bars pivot. Lazy tongs and omnigraph name the same linkage, and the train's current collector borrows its shape.

2. 2
   nouncountable

   A spring-loaded, usually Z-shaped conductive arm mounted on the roof of a train or tram that presses against overhead lines to collect electric current.

   Maintenance crews inspect each pantograph for worn contact strips before the morning service.

   As the locomotive accelerated, its pantograph traced the overhead wire without losing contact.

   Note

   Railway engineers took the name for a hinged, folding frame from the same family of linkage as the drawing instrument. Diamond-shaped collectors were once common, and the Z-shaped arm is now the norm. At the top, a carbon contact strip rides the overhead catenary wire under spring pressure. The strip is the part that wears, not the frame, so it is what crews check.

3. 3
   nouncountable

   A structure of crosswise bars linked so that it extends and compresses like an accordion, as in an extendable mirror or a scissor lift.

   The wall-mounted pantograph swung the shaving mirror out over the sink.

   Engineers chose a pantograph to raise the work platform smoothly to height.

   Note

   Here the word keeps the shape and drops the copying. Crossed bars are linked so the whole frame stretches out and folds back flat, and nothing is drawn or traced. The noun often works as a modifier, as in pantograph mirror, and the same frame stands under a scissor lift. The drawing instrument supplied the geometry, but not the job.

4. 4
   nouncountable

   A background pattern printed on a document so that photocopying it produces a degraded image or reveals a hidden warning, deterring counterfeiting.

   The bank prints a pantograph behind the amount field to foil altered duplicates.

   Security designers added a pantograph that renders the word "copy" visible on any reproduction.

5. 5
   verbtransitive

   To engrave a design or lettering by guiding a jointed parallel-linkage machine that copies a master pattern onto the workpiece.

   Craftsmen pantograph the regimental crest onto each presentation sword.

   Machinists still pantograph mold cavities from oversized templates.

   Note

   A verb made straight from the machine, and a regular one: pantographs, pantographing, pantographed. It is transitive and usually names where the design goes, so a crest is pantographed onto a blade. The usual direction is reduction. A stylus follows an oversized master while a coupled cutter carves the design smaller, which reverses the draftsman's habit of enlarging.

Showing meanings only. Show all 5