APPARATUS FOR APPLYING A CONTROLLED FORCE TO AN ARTICLE
Apparatus, such a embossing apparatus, for applying a controlled amount of force to an article comprises a head ( 26 ) for engaging such an article to apply said force. The head ( 26 ) is moveable along substantially linear operating or return strokes, and is mounted on a rigid support ( 1, 2 ) through flexure means such a plate ( 32, 40 ). The flexure means constrains the head ( 26 ) so that latter moves only in the direction of said strokes.
1 . Apparatus for applying a controlled amount of force to an article, the apparatus comprising a head for engaging such an article to apply said force, the head being moveable along substantially linear operating or return strokes; flexure means through which the head is mounted on a substantially rigid support means, and an actuator for moving the head, wherein the flexure means is so arranged as to constrain the head so that the latter moves only in the direction of said strokes.
2 . Apparatus according to claim 1 , in which the apparatus is adapted for use in a process of creating surface features on an article, for example an embossing or imprinting process.
3 . Apparatus according to claim 1 , in which the apparatus is embossing apparatus.
4 . Apparatus according to claim 3 , in which the apparatus includes an embossing or imprinting tool which is urged against the article by the action of the head.
5 . Apparatus according to claim 1 , in which the actuator is operable to drive the head along its operating stroke.
6 . Apparatus according to claim 1 , in which the actuator comprises a piezoactuator.
7 . Apparatus according to claim 1 , in which the flexure means is resilient so as to exert on the head a biasing force in the direction of the return stroke.
8 . Apparatus according to claim 1 , in which the flexure means comprises a plate.
9 . Apparatus according to claim 8 , in which the direction of each stroke is substantially perpendicular to the plate.
10 . Apparatus according to claim 8 , in which the plate is symmetrically arranged relative to the head.
11 . Apparatus according to claim 10 , in which the plate is circular and concentric with the head.
12 . Apparatus according to claim 8 , in which the apparatus includes one or more conduits for enabling gas pressure on either side of the plate to be equalized.
13 . Apparatus according to claim 12 , in which the or each conduit is provided in the plate.
14 . Apparatus according to claim 8 in which the plate is one of two such plates which are parallel to each other and are spaced from each other in the direction of the strokes.
15 . Apparatus according to claim 6 , in which the piezoactuator is connected to the head through a linkage for providing mechanical amplification of the actuator stroke.
16 . Apparatus according to claim 15 , in which the linkage comprises a rod attached to the head and a lever attaching the rod to the actuator.
17 . Apparatus according to claim 1 , which the rigid support means comprises a frame on which the flexure means is mounted.
18 . Embossing apparatus comprising a head for urging an embossing tool and an article together to cause the article to be embossed, a piezoactuator for moving the head relative to a support frame and flexure means mounting the head on the frame.
19 . Embossing apparatus according to claim 18 , in which the piezoactuator and rod are disposed substantially parallel and adjacent to each other, the piezoactuator having an operating stroke in the opposite direction to that of the head, and hence the rod.