초록 ▼

An arm assembly includes an outer stem (52) and an inner stem (50) slidable in the outer stem and including a number of recesses (107) along its length. A biased locking device (117) engages one or more of the recesses (107) to lock the position of the inner stem (50) relative to the outer stem (52)

An arm assembly includes an outer stem (52) and an inner stem (50) slidable in the outer stem and including a number of recesses (107) along its length. A biased locking device (117) engages one or more of the recesses (107) to lock the position of the inner stem (50) relative to the outer stem (52). A release member (103) operably connected to an actuator (101) has a number of recesses (110) and raised surfaces (112), the release member (103) slidable relative to the inner stem (50) between a first position in which recess(es) (110) in the release member is/are aligned with recess(es) (107) of the inner stem and the locking device (117) engages recess(es) in the stem (50) to inhibit movement thereof relative to the outer stem, and a second position in which raised surface(s) (112) of the release member align(s) with recess(es) (107) of the stem (50) to disengage the locking device from the recess(es) of the stem.

대표청구항 ▼

1. A height adjustable arm assembly for a chair comprising:an outer stem attachable to a first chair component; an inner stem attachable to a second chair component and slidably received in the outer stem and including a plurality of recesses spaced along a length thereof; a locking device biased to

1. A height adjustable arm assembly for a chair comprising:an outer stem attachable to a first chair component; an inner stem attachable to a second chair component and slidably received in the outer stem and including a plurality of recesses spaced along a length thereof; a locking device biased to engage one or more of the plurality of recesses to lock the position of the inner stem relative to the outer stem; and a release member in operable connection with an actuator and having a plurality of recesses with raised surfaces therebetween, the release member being slidably moveable relative to the inner stem between a first position in which at least one of the recesses in the release member is aligned with at least one of the recesses of the inner stem and the locking device engages at least one of the recesses in the inner stem to inhibit movement of the inner stem relative to the outer stem, and a second position in which one or more of the raised surfaces of the release member aligns with the one or more recesses of the inner stem to remove the locking device from engagement with the recess or recesses and to provide a surface over which the locking device can slide to enable relative movement between the inner stem and the outer stem. 2. A height adjustable arm assembly as claimed in claim 1, wherein the release member comprises camming surfaces adjacent the recesses, the camming surfaces configured so that when one of the camming surfaces is moved into alignment with the recess or recesses of the inner stem with which the locking device is engaged, the locking device is progressively forced from engagement with said recess or recesses of the inner stem.3. A height adjustable arm assembly as claimed in claim 2, wherein the raised surfaces of the release member are provided between respective camming surfaces and respective following recesses, such that initial movement of the release member progressively forces the locking device from the recess or recesses of the inner stem, and further movement brings one of the raised surfaces into alignment with the recess or recesses of the inner stem.4. A height adjustable arm assembly as claimed in claim 1, wherein the inner stem comprises a longitudinal channel adjacent the plurality of recesses, and the release member is slidably mounted in the longitudinal channel.5. A height adjustable arm assembly as claimed in claim 1, wherein the inner stem comprises two rows of recesses with the channel being defined between the rows of recesses, and the release member is slidably mounted in the longitudinal channel between the two rows of recesses.6. A height adjustable arm assembly as claimed in claim 1, wherein a liner is mounted in the outer stem, with the moving inner stem telescopically received in the liner.7. A height adjustable arm assembly as claimed in claim 6, wherein the liner is a two-piece liner.8. A height adjustable arm assembly as claimed in claim 6, wherein the liner is made of a plastics material.9. A height adjustable arm assembly as claimed in claim 6, wherein the liner comprises an aperture for receipt of the locking device, and the locking device extends inwardly through the aperture.10. A height adjustable arm assembly as claimed in claim 9, wherein the liner comprises a strengthened region adjacent the aperture for receipt of the locking device, to enhance the rigidity of the locking device.11. A height adjustable arm assembly as claimed in claim 6, wherein the liner comprises an outwardly-extending leaf spring to reduce slack between the liner and the outer stem.12. A height adjustable arm assembly as claimed in claim 6, wherein the liner comprises an inwardly-extending leaf spring to reduce slack between the liner and in the inner stem.13. A height adjustable arm assembly as claimed in claim 6, wherein the locking device comprises a locking pin which is biased towards the recesses of the inner stem.14. A height adjustable arm assembly as claimed in claim 13, wherein a coil spring extends between a surface of the outer stem and the locking pin, to bias the locking pin towards the recesses.15. A height adjustable arm assembly as claimed in claim 13, wherein a leaf spring or spring wire biases the locking pin towards the recesses of the inner stem.16. A height adjustable arm assembly as claimed in claim 15, wherein the liner comprises a groove for receipt of the leaf spring or spring wire which extends behind the locking pin to bias the locking pin towards the recesses of the inner stem.17. A height adjustable arm assembly as claimed in claim 16, wherein the liner comprises strengthening ribs, and the groove is defined by an undercut in one or more of the strengthening ribs.18. A height adjustable arm assembly as claimed in claim 1, wherein the locking device comprises a locking pin which is biased towards the recesses of the inner stem.19. A height adjustable arm assembly as claimed in claim 18, wherein a coil spring extends between a surface of the outer stem and the locking pin, to bias the locking pin towards the recesses.20. A height adjustable arm assembly as claimed in claim 18, wherein a leaf spring or spring wire biases the locking pin towards the recesses of the inner stem.21. A height adjustable arm assembly as claimed claim 1, wherein the outer stem comprises a stem cap to close off the end of the outer stem opposite to the end through which the inner stem extends22. A height adjustable arm assembly as claimed in claim 1, wherein the release member comprises an elongate member.23. A height adjustable arm assembly as claimed in claim 22, wherein the release member comprises a rod.24. A height adjustable arm assembly as claimed claim 1, wherein the recesses in the inner stem and in the release member are in the form of notches.25. A height adjustable arm assembly as claimed in claim 1, wherein the inner stem is an upper stem configured for attachment to an armrest, and the outer stem is a lower stem configured for attachment to a chair.26. A height adjustable arm assembly as claimed in claim 25, wherein a camming surface defines an edge of each recess of the release member towards the outer stem, such that movement of the release member away from the outer stem forces the locking device from the recess or recesses of the inner stem.27. A height adjustable arm assembly as claimed in claim 26, wherein the release member is biased in a direction toward the outer stem.28. A height adjustable arm assembly as claimed in claim 26, wherein the actuator comprises a height adjustment lever extending through the inner stem at or adjacent an end thereof distal from the outer stem, which lever is in operable engagement with the release member.29. A height adjustable arm assembly as claimed in claim 28, wherein the lever is slidably mounted in the inner stem such that moving the lever in a direction away from the outer stem moves the release member in a direction away from the outer stem and thereby forces the locking device from the recess or recesses of the inner stem, enabling the relative positions of the inner and outer stems to be adjusted.30. A height adjustable arm assembly as claimed in claim 25, wherein a camming surface defines an edge of each recess of the release member away from the outer stem, such that movement of the release member towards the outer stem forces the locking device from the recess or recesses of the inner stem.31. A height adjustable arm assembly as claimed in claim 30, wherein the release member is biased in a direction away from the inner stem.32. A height adjustable arm assembly as claimed in claim 30, wherein the actuator comprises a height adjustment lever extending through the inner stem at or adjacent an end thereof distal from the outer stem, which lever is in operable engagement with the release member.33. A height adjustable arm assembly as claimed in claim 32, wherein the lever is pivotally mounted to the inner stem such that moving an outer part of the lever in a direction away from the outer stem moves the release member toward the outer stem and thereby forces the locking device from the recess or recesses of the inner stem, enabling the relative positions of the inner and outer stems to be adjusted.34. A height adjustable arm assembly as claimed in claim 1, wherein the inner stem is a lower stem configured for attachment to a chair, and the outer stem is an upper stem configured for attachment to an armrest.35. A height adjustable arm assembly as claimed in claim 34, wherein a camming surface defines an edge of each recess of the release member towards the outer stem, such that movement of the release member away from the outer stem forces the locking device from the recess or recesses of the inner stem.36. A height adjustable arm assembly as claimed in claim 35, wherein the release member is biased in a direction toward the outer stem.37. A height adjustable arm assembly as claimed in claim 35, wherein the actuator comprises a height adjustment lever extending through the outer stem at or adjacent an end thereof distal from the inner stem, which lever is in operable engagement with the release member.38. A height adjustable arm assembly as claimed in claim 37, wherein the lever is pivotally mounted to the outer stem such that moving an outer part of the lever away from the inner stem moves the release member away from the outer stem and thereby forces the locking device from the recess or recesses of the inner stem, enabling the relative positions of the inner and outer stems to be adjusted39. A height adjustable arm assembly as claimed in claim 34, wherein a camming surface defines an edge of each recess of the release member away from the outer stem, such that movement of the release member towards the outer stem forces the locking device from the recess or recesses of the inner stem.40. A height adjustable arm assembly as claimed in claim 39, wherein the release member is biased in a direction away from the inner stem.41. A height adjustable arm assembly as claimed in claim 39, wherein the actuator comprises a height adjustment lever extending through the inner stem at or adjacent an end thereof distal from the inner stem, which lever is in operable engagement with the release member.42. A height adjustable arm assembly as claimed in claim 41, wherein the lever is slidably mounted to the outer stem such that moving the lever in a direction away from the inner stem moves the release member toward the outer stem and thereby forces the locking device from the recess or recesses of the inner stem, enabling the relative positions of the inner and outer stems to be adjusted.43. A height adjustable arm assembly as claimed in claim 1, comprising a cover which covers the recesses of the inner stem and the release member.44. A height adjustable arm assembly as claimed in claim 43, and including a liner in the outer stem, wherein the cover comprises a tongue extending from the liner.45. An office chair comprising a pair of height adjustable arm assemblies as claimed in claim 1 attached thereto, the arm assemblies supporting armrests from the chair.