Position and Presence Sensing

Position and Presence Sensing within Sensors, Controls & Machine Vision.

Category CAT-000000245

Subcategories

Publications

• OT-2026-000007847
  Two finger electric gripper, stripped after set-down, on a tool changer
  September 17, 2026 · Mechanical Grippers · 739 words

  A mechanical finger gripper comprising one tool-change interface, two gripper fingers, one contact detector and one separating element. When the gripper reaches the gripping position, the gripper fingers are closed by the electric actuator. After the gripper fingers have been opened, the workpiece is released by the se

• OT-2026-000007849
  Three cup vacuum gripper, three zone face, three outlet manifold, plant vacuum fed, manifold pressure sensor, pulsed blow-off after set-down, on a tool changer
  September 17, 2026 · Vacuum Grippers · 1,233 words

  A zoned vacuum gripping tool comprising one tool-change interface, three suction cups, one plant vacuum connection, one manifold, three zone branches, one pressure sensor, one contact detector and one blow-off valve. When the suction cups reach the workpiece, the suction cups are evacuated by the plant vacuum connectio

• OT-2026-000007850
  Three bellows cup vacuum gripper, three zone face, per zone isolation, single stage ejector, supply line pressure sensor, vented before set-down, on a tool changer
  September 17, 2026 · Vacuum Grippers · 1,433 words

  A zoned vacuum gripping tool comprising one tool-change interface, three bellows cups, one ejector, three isolation valves, three zone branches, one pressure sensor, one contact detector and one vent valve. When the bellows cups reach the workpiece, the bellows cups are evacuated by the ejector. Before the workpiece re

• OT-2026-000007852
  Four bellows cup vacuum gripper, four zone face, six outlet manifold, pump fed, vented after set-down, on a tool changer
  September 17, 2026 · Vacuum Grippers · 1,048 words

  A zoned vacuum gripping tool comprising one tool-change interface, four bellows cups, one vacuum pump, one manifold, four zone branches, one contact detector and one vent valve. When the bellows cups reach the workpiece, the bellows cups are evacuated by the vacuum pump. After the workpiece has reached the set-down pos

• OT-2026-000007854
  Foam pad vacuum gripper, common isolation valve, plant vacuum fed, supply line pressure sensor, sustained blow-off before set-down
  September 17, 2026 · Vacuum Grippers · 1,239 words

  A foam-pad vacuum gripping tool comprising one mounting flange, one foam pad, one plant vacuum connection, one isolation valve, one pressure sensor, one contact detector and one blow-off valve. When the foam pad reaches the workpiece, the foam pad is evacuated by the plant vacuum connection. Before the workpiece reache

• OT-2026-000007856
  Four bellows cup vacuum gripper, four zone face, common isolation valve, plant vacuum fed, supply line pressure sensor, pulsed blow-off after set-down, on a tool changer
  September 17, 2026 · Vacuum Grippers · 1,288 words

  A zoned vacuum gripping tool comprising one tool-change interface, four bellows cups, one plant vacuum connection, one isolation valve, four zone branches, one pressure sensor, one contact detector and one blow-off valve. When the bellows cups reach the workpiece, the bellows cups are evacuated by the plant vacuum conn

• OT-2026-000007857
  Two bellows cup vacuum gripper, two outlet manifold, common isolation valve, two stage ejector, supply line pressure sensor, sustained blow-off before set-down, on a tool changer
  September 17, 2026 · Vacuum Grippers · 1,370 words

  A bellows-cup vacuum gripping tool comprising one tool-change interface, two bellows cups, one ejector, one isolation valve, one manifold, one pressure sensor, one contact detector and one blow-off valve. When the bellows cups reach the workpiece, the bellows cups are evacuated by the ejector. Before the workpiece reac

• OT-2026-000007858
  Four pad foam vacuum gripper, four outlet manifold, common isolation valve, three stage ejector, supply line pressure sensor, pulsed blow-off before set-down, on a tool changer
  September 17, 2026 · Vacuum Grippers · 1,464 words

  A foam-pad vacuum gripping tool comprising one tool-change interface, four foam pads, one ejector, one isolation valve, one manifold, one pressure sensor, one contact detector and one blow-off valve. When the foam pads reach the workpiece, the foam pads are evacuated by the ejector. Before the workpiece reaches the set

• OT-2026-000007859
  Three cup vacuum gripper, three outlet manifold, common isolation valve, single stage ejector, manifold pressure sensor, vented before set-down
  September 17, 2026 · Vacuum Grippers · 1,198 words

  A suction-cup vacuum gripping tool comprising one mounting flange, three suction cups, one ejector, one isolation valve, one manifold, one pressure sensor, one contact detector and one vent valve. When the suction cups reach the workpiece, the suction cups are evacuated by the ejector. Before the workpiece reaches the

• OT-2026-000007860
  Three bellows cup vacuum gripper, three zone face, three outlet manifold, pump fed, pressure sensor per zone, vented after set-down
  September 17, 2026 · Vacuum Grippers · 1,126 words

  A zoned vacuum gripping tool comprising one mounting flange, three bellows cups, one vacuum pump, one manifold, three zone branches, three pressure sensors, one contact detector and one vent valve. When the bellows cups reach the workpiece, the bellows cups are evacuated by the vacuum pump. After the workpiece has reac

• OT-2026-000007863
  Four pad foam vacuum gripper, four outlet manifold, common isolation valve, two stage ejector, vented after set-down
  September 17, 2026 · Vacuum Grippers · 995 words

  A foam-pad vacuum gripping tool comprising one mounting flange, four foam pads, one ejector, one isolation valve, one manifold, one contact detector and one vent valve. When the foam pads reach the workpiece, the foam pads are evacuated by the ejector. After the workpiece has reached the set-down position, the vacuum c

• OT-2026-000007864
  Single cup vacuum gripper, common isolation valve, pump fed, supply line pressure sensor, sustained blow-off after set-down, on a tool changer
  September 17, 2026 · Vacuum Grippers · 1,199 words

  A suction-cup vacuum gripping tool comprising one tool-change interface, one suction cup, one vacuum pump, one isolation valve, one pressure sensor, one contact detector and one blow-off valve. When the suction cup reaches the workpiece, the suction cup is evacuated by the vacuum pump. After the workpiece has reached t

• OT-2026-000007869
  Foam pad vacuum gripper, two zone face, common isolation valve, two stage ejector, pressure sensor per zone, sustained blow-off before set-down
  September 17, 2026 · Vacuum Grippers · 1,405 words

  A zoned vacuum gripping tool comprising one mounting flange, one foam pad, one ejector, one isolation valve, two zone branches, two pressure sensors, one contact detector and one blow-off valve. When the foam pad reaches the workpiece, the foam pad is evacuated by the ejector. Before the workpiece reaches the set-down

• OT-2026-000007871
  Six bellows cup vacuum gripper, six outlet manifold, common isolation valve, two stage ejector, manifold pressure sensor, vented after set-down, on a tool changer
  September 17, 2026 · Vacuum Grippers · 1,243 words

  A bellows-cup vacuum gripping tool comprising one tool-change interface, six bellows cups, one ejector, one isolation valve, one manifold, one pressure sensor, one contact detector and one vent valve. When the bellows cups reach the workpiece, the bellows cups are evacuated by the ejector. After the workpiece has reach

• OT-2026-000007872
  Three bellows cup vacuum gripper, three zone face, three stage ejector, supply line pressure sensor, sustained blow-off before set-down
  September 17, 2026 · Vacuum Grippers · 1,190 words

  A zoned vacuum gripping tool comprising one mounting flange, three bellows cups, one ejector, three zone branches, one pressure sensor, one contact detector and one blow-off valve. When the bellows cups reach the workpiece, the bellows cups are evacuated by the ejector. Before the workpiece reaches the set-down positio

• OT-2026-000007873
  Four bellows cup vacuum gripper, four zone face, per zone isolation, two stage ejector, supply line pressure sensor, pulsed blow-off after set-down
  September 17, 2026 · Vacuum Grippers · 1,341 words

  A zoned vacuum gripping tool comprising one mounting flange, four bellows cups, one ejector, four isolation valves, four zone branches, one pressure sensor, one contact detector and one blow-off valve. When the bellows cups reach the workpiece, the bellows cups are evacuated by the ejector. After the workpiece has reac

• OT-2026-000007875
  Three cup vacuum gripper, three outlet manifold, plant vacuum fed, sustained blow-off before set-down, on a tool changer
  September 17, 2026 · Vacuum Grippers · 1,008 words

  A suction-cup vacuum gripping tool comprising one tool-change interface, three suction cups, one plant vacuum connection, one manifold, one contact detector and one blow-off valve. When the suction cups reach the workpiece, the suction cups are evacuated by the plant vacuum connection. Before the workpiece reaches the

• OT-2026-000007878
  Six bellows cup vacuum gripper, six outlet manifold, common isolation valve, two stage ejector, manifold pressure sensor, pulsed blow-off before set-down, on a tool changer
  September 17, 2026 · Vacuum Grippers · 1,348 words

  A bellows-cup vacuum gripping tool comprising one tool-change interface, six bellows cups, one ejector, one isolation valve, one manifold, one pressure sensor, one contact detector and one blow-off valve. When the bellows cups reach the workpiece, the bellows cups are evacuated by the ejector. Before the workpiece reac

• OT-2026-000007879
  Four pad foam vacuum gripper, four outlet manifold, common isolation valve, three stage ejector, manifold pressure sensor, vented before set-down
  September 17, 2026 · Vacuum Grippers · 1,271 words

  A foam-pad vacuum gripping tool comprising one mounting flange, four foam pads, one ejector, one isolation valve, one manifold, one pressure sensor, one contact detector and one vent valve. When the foam pads reach the workpiece, the foam pads are evacuated by the ejector. Before the workpiece reaches the set-down posi

• OT-2026-000007880
  Three bellows cup vacuum gripper, three zone face, three outlet manifold, two stage ejector, pressure sensor per zone, pulsed blow-off after set-down
  September 17, 2026 · Vacuum Grippers · 1,224 words

  A zoned vacuum gripping tool comprising one mounting flange, three bellows cups, one ejector, one manifold, three zone branches, three pressure sensors, one contact detector and one blow-off valve. When the bellows cups reach the workpiece, the bellows cups are evacuated by the ejector. After the workpiece has reached

• OT-2026-000007882
  Four pad foam vacuum gripper, four outlet manifold, common isolation valve, single stage ejector, manifold pressure sensor, vented before set-down
  September 17, 2026 · Vacuum Grippers · 1,252 words

  A foam-pad vacuum gripping tool comprising one mounting flange, four foam pads, one ejector, one isolation valve, one manifold, one pressure sensor, one contact detector and one vent valve. When the foam pads reach the workpiece, the foam pads are evacuated by the ejector. Before the workpiece reaches the set-down posi

• OT-2026-000007883
  Four bellows cup vacuum gripper, four outlet manifold, single stage ejector, pulsed blow-off after set-down, on a tool changer
  September 17, 2026 · Vacuum Grippers · 1,003 words

  A bellows-cup vacuum gripping tool comprising one tool-change interface, four bellows cups, one ejector, one manifold, one contact detector and one blow-off valve. When the bellows cups reach the workpiece, the bellows cups are evacuated by the ejector. After the workpiece has reached the set-down position, the workpie

• OT-2026-000007884
  Four bellows cup vacuum gripper, four zone face, common isolation valve, pump fed, pressure sensor per zone, sustained blow-off after set-down, on a tool changer
  September 17, 2026 · Vacuum Grippers · 1,394 words

  A zoned vacuum gripping tool comprising one tool-change interface, four bellows cups, one vacuum pump, one isolation valve, four zone branches, four pressure sensors, one contact detector and one blow-off valve. When the bellows cups reach the workpiece, the bellows cups are evacuated by the vacuum pump. After the work

• OT-2026-000007885
  Foam pad vacuum gripper, three zone face, four outlet manifold, pump fed, vented after set-down
  September 17, 2026 · Vacuum Grippers · 979 words

  A zoned vacuum gripping tool comprising one mounting flange, one foam pad, one vacuum pump, one manifold, three zone branches, one contact detector and one vent valve. When the foam pad reaches the workpiece, the foam pad is evacuated by the vacuum pump. After the workpiece has reached the set-down position, the vacuum

• OT-2026-000007888
  Three cup vacuum gripper, three outlet manifold, common isolation valve, two stage ejector, supply line pressure sensor, sustained blow-off after set-down, on a tool changer
  September 17, 2026 · Vacuum Grippers · 1,331 words

  A suction-cup vacuum gripping tool comprising one tool-change interface, three suction cups, one ejector, one isolation valve, one manifold, one pressure sensor, one contact detector and one blow-off valve. When the suction cups reach the workpiece, the suction cups are evacuated by the ejector. After the workpiece has

• OT-2026-000007889
  Four cup vacuum gripper, four outlet manifold, common isolation valve, pump fed, pulsed blow-off after set-down
  September 17, 2026 · Vacuum Grippers · 1,044 words

  A suction-cup vacuum gripping tool comprising one mounting flange, four suction cups, one vacuum pump, one isolation valve, one manifold, one contact detector and one blow-off valve. When the suction cups reach the workpiece, the suction cups are evacuated by the vacuum pump. After the workpiece has reached the set-dow

• OT-2026-000007891
  Three bellows cup vacuum gripper, three zone face, per zone isolation, plant vacuum fed, vented after set-down, on a tool changer
  September 17, 2026 · Vacuum Grippers · 1,127 words

  A zoned vacuum gripping tool comprising one tool-change interface, three bellows cups, one plant vacuum connection, three isolation valves, three zone branches, one contact detector and one vent valve. When the bellows cups reach the workpiece, the bellows cups are evacuated by the plant vacuum connection. After the wo

• OT-2026-000007892
  Two bellows cup vacuum gripper, two outlet manifold, plant vacuum fed, vented before set-down, on a tool changer
  September 17, 2026 · Vacuum Grippers · 939 words

  A bellows-cup vacuum gripping tool comprising one tool-change interface, two bellows cups, one plant vacuum connection, one manifold, one contact detector and one vent valve. When the bellows cups reach the workpiece, the bellows cups are evacuated by the plant vacuum connection. Before the workpiece reaches the set-do

• OT-2026-000007893
  Single cup vacuum gripper, common isolation valve, single stage ejector, supply line pressure sensor, pulsed blow-off before set-down
  September 17, 2026 · Vacuum Grippers · 1,225 words

  A suction-cup vacuum gripping tool comprising one mounting flange, one suction cup, one ejector, one isolation valve, one pressure sensor, one contact detector and one blow-off valve. When the suction cup reaches the workpiece, the suction cup is evacuated by the ejector. Before the workpiece reaches the set-down posit

• OT-2026-000007894
  Foam pad vacuum gripper, four zone face, per zone isolation, three stage ejector, pressure sensor per zone, pulsed blow-off after set-down, on a tool changer
  September 17, 2026 · Vacuum Grippers · 1,540 words

  A zoned vacuum gripping tool comprising one tool-change interface, one foam pad, one ejector, four isolation valves, four zone branches, four pressure sensors, one contact detector and one blow-off valve. When the foam pad reaches the workpiece, the foam pad is evacuated by the ejector. After the workpiece has reached

• OT-2026-000007896
  Three cup vacuum gripper, three zone face, six outlet manifold, pump fed, vented after set-down
  September 17, 2026 · Vacuum Grippers · 949 words

  A zoned vacuum gripping tool comprising one mounting flange, three suction cups, one vacuum pump, one manifold, three zone branches, one contact detector and one vent valve. When the suction cups reach the workpiece, the suction cups are evacuated by the vacuum pump. After the workpiece has reached the set-down positio

• OT-2026-000007897
  Two cup vacuum gripper, two zone face, per zone isolation, two stage ejector, pressure sensor per zone, vented after set-down, on a tool changer
  September 17, 2026 · Vacuum Grippers · 1,422 words

  A zoned vacuum gripping tool comprising one tool-change interface, two suction cups, one ejector, two isolation valves, two zone branches, two pressure sensors, one contact detector and one vent valve. When the suction cups reach the workpiece, the suction cups are evacuated by the ejector. After the workpiece has reac

• OT-2026-000007898
  Foam pad vacuum gripper, three zone face, three outlet manifold, plant vacuum fed, pulsed blow-off after set-down, on a tool changer
  September 17, 2026 · Vacuum Grippers · 1,091 words

  A zoned vacuum gripping tool comprising one tool-change interface, one foam pad, one plant vacuum connection, one manifold, three zone branches, one contact detector and one blow-off valve. When the foam pad reaches the workpiece, the foam pad is evacuated by the plant vacuum connection. After the workpiece has reached

• OT-2026-000007902
  Foam pad vacuum gripper, three stage ejector, supply line pressure sensor, pulsed blow-off after set-down
  September 17, 2026 · Vacuum Grippers · 1,036 words

  A foam-pad vacuum gripping tool comprising one mounting flange, one foam pad, one ejector, one pressure sensor, one contact detector and one blow-off valve. When the foam pad reaches the workpiece, the foam pad is evacuated by the ejector. After the workpiece has reached the set-down position, the workpiece is blown of

• OT-2026-000007903
  Three bellows cup vacuum gripper, three outlet manifold, two stage ejector, manifold pressure sensor, sustained blow-off before set-down, on a tool changer
  September 17, 2026 · Vacuum Grippers · 1,196 words

  A bellows-cup vacuum gripping tool comprising one tool-change interface, three bellows cups, one ejector, one manifold, one pressure sensor, one contact detector and one blow-off valve. When the bellows cups reach the workpiece, the bellows cups are evacuated by the ejector. Before the workpiece reaches the set-down po

• OT-2026-000007905
  Six cup vacuum gripper, six outlet manifold, common isolation valve, three stage ejector, manifold pressure sensor, vented after set-down, on a tool changer
  September 17, 2026 · Vacuum Grippers · 1,229 words

  A suction-cup vacuum gripping tool comprising one tool-change interface, six suction cups, one ejector, one isolation valve, one manifold, one pressure sensor, one contact detector and one vent valve. When the suction cups reach the workpiece, the suction cups are evacuated by the ejector. After the workpiece has reach

• OT-2026-000007907
  Six pad foam vacuum gripper, six outlet manifold, common isolation valve, plant vacuum fed, manifold pressure sensor, sustained blow-off after set-down, on a tool changer
  September 17, 2026 · Vacuum Grippers · 1,294 words

  A foam-pad vacuum gripping tool comprising one tool-change interface, six foam pads, one plant vacuum connection, one isolation valve, one manifold, one pressure sensor, one contact detector and one blow-off valve. When the foam pads reach the workpiece, the foam pads are evacuated by the plant vacuum connection. After

• OT-2026-000007908
  Six pad foam vacuum gripper, six outlet manifold, common isolation valve, pump fed, vented after set-down, on a tool changer
  September 17, 2026 · Vacuum Grippers · 1,093 words

  A foam-pad vacuum gripping tool comprising one tool-change interface, six foam pads, one vacuum pump, one isolation valve, one manifold, one contact detector and one vent valve. When the foam pads reach the workpiece, the foam pads are evacuated by the vacuum pump. After the workpiece has reached the set-down position,

• OT-2026-000007909
  Four bellows cup vacuum gripper, four zone face, six outlet manifold, two stage ejector, vented before set-down, on a tool changer
  September 17, 2026 · Vacuum Grippers · 1,109 words

  A zoned vacuum gripping tool comprising one tool-change interface, four bellows cups, one ejector, one manifold, four zone branches, one contact detector and one vent valve. When the bellows cups reach the workpiece, the bellows cups are evacuated by the ejector. Before the workpiece reaches the set-down position, the

• OT-2026-000007910
  Foam pad vacuum gripper, two zone face, common isolation valve, three stage ejector, vented before set-down, on a tool changer
  September 17, 2026 · Vacuum Grippers · 1,200 words

  A zoned vacuum gripping tool comprising one tool-change interface, one foam pad, one ejector, one isolation valve, two zone branches, one contact detector and one vent valve. When the foam pad reaches the workpiece, the foam pad is evacuated by the ejector. Before the workpiece reaches the set-down position, the vacuum

• OT-2026-000007911
  Three cup vacuum gripper, three zone face, per zone isolation, plant vacuum fed, supply line pressure sensor, vented after set-down, on a tool changer
  September 17, 2026 · Vacuum Grippers · 1,356 words

  A zoned vacuum gripping tool comprising one tool-change interface, three suction cups, one plant vacuum connection, three isolation valves, three zone branches, one pressure sensor, one contact detector and one vent valve. When the suction cups reach the workpiece, the suction cups are evacuated by the plant vacuum con

• OT-2026-000007912
  Four cup vacuum gripper, four outlet manifold, common isolation valve, two stage ejector, manifold pressure sensor, vented before set-down, on a tool changer
  September 17, 2026 · Vacuum Grippers · 1,251 words

  A suction-cup vacuum gripping tool comprising one tool-change interface, four suction cups, one ejector, one isolation valve, one manifold, one pressure sensor, one contact detector and one vent valve. When the suction cups reach the workpiece, the suction cups are evacuated by the ejector. Before the workpiece reaches

• OT-2026-000007913
  Three cup vacuum gripper, three zone face, common isolation valve, plant vacuum fed, vented before set-down
  September 17, 2026 · Vacuum Grippers · 1,034 words

  A zoned vacuum gripping tool comprising one mounting flange, three suction cups, one plant vacuum connection, one isolation valve, three zone branches, one contact detector and one vent valve. When the suction cups reach the workpiece, the suction cups are evacuated by the plant vacuum connection. Before the workpiece

• OT-2026-000007915
  Six cup vacuum gripper, six outlet manifold, common isolation valve, three stage ejector, supply line pressure sensor, pulsed blow-off after set-down
  September 17, 2026 · Vacuum Grippers · 1,218 words

  A suction-cup vacuum gripping tool comprising one mounting flange, six suction cups, one ejector, one isolation valve, one manifold, one pressure sensor, one contact detector and one blow-off valve. When the suction cups reach the workpiece, the suction cups are evacuated by the ejector. After the workpiece has reached

• OT-2026-000007916
  Three cup vacuum gripper, three outlet manifold, single stage ejector, supply line pressure sensor, vented before set-down, on a tool changer
  September 17, 2026 · Vacuum Grippers · 1,142 words

  A suction-cup vacuum gripping tool comprising one tool-change interface, three suction cups, one ejector, one manifold, one pressure sensor, one contact detector and one vent valve. When the suction cups reach the workpiece, the suction cups are evacuated by the ejector. Before the workpiece reaches the set-down positi

• OT-2026-000007917
  Foam pad vacuum gripper, two stage ejector, supply line pressure sensor, sustained blow-off before set-down, on a tool changer
  September 17, 2026 · Vacuum Grippers · 1,180 words

  A foam-pad vacuum gripping tool comprising one tool-change interface, one foam pad, one ejector, one pressure sensor, one contact detector and one blow-off valve. When the foam pad reaches the workpiece, the foam pad is evacuated by the ejector. Before the workpiece reaches the set-down position, the workpiece is blown

• OT-2026-000007918
  Four cup vacuum gripper, four zone face, common isolation valve, two stage ejector, sustained blow-off after set-down, on a tool changer
  September 17, 2026 · Vacuum Grippers · 1,139 words

  A zoned vacuum gripping tool comprising one tool-change interface, four suction cups, one ejector, one isolation valve, four zone branches, one contact detector and one blow-off valve. When the suction cups reach the workpiece, the suction cups are evacuated by the ejector. After the workpiece has reached the set-down

• OT-2026-000007919
  Foam pad vacuum gripper, four zone face, common isolation valve, pump fed, vented after set-down, on a tool changer
  September 17, 2026 · Vacuum Grippers · 1,133 words

  A zoned vacuum gripping tool comprising one tool-change interface, one foam pad, one vacuum pump, one isolation valve, four zone branches, one contact detector and one vent valve. When the foam pad reaches the workpiece, the foam pad is evacuated by the vacuum pump. After the workpiece has reached the set-down position

• OT-2026-000007920
  Four bellows cup vacuum gripper, four outlet manifold, three stage ejector, sustained blow-off before set-down
  September 17, 2026 · Vacuum Grippers · 966 words

  A bellows-cup vacuum gripping tool comprising one mounting flange, four bellows cups, one ejector, one manifold, one contact detector and one blow-off valve. When the bellows cups reach the workpiece, the bellows cups are evacuated by the ejector. Before the workpiece reaches the set-down position, the workpiece is blo

• OT-2026-000007921
  Three cup vacuum gripper, three zone face, four outlet manifold, pump fed, manifold pressure sensor, pulsed blow-off before set-down, on a tool changer
  September 17, 2026 · Vacuum Grippers · 1,341 words

  A zoned vacuum gripping tool comprising one tool-change interface, three suction cups, one vacuum pump, one manifold, three zone branches, one pressure sensor, one contact detector and one blow-off valve. When the suction cups reach the workpiece, the suction cups are evacuated by the vacuum pump. Before the workpiece