Joints and connections – Articulated members – Lockable at fixed position
Patent
1999-03-04
2000-11-28
Browne, Lynne H.
Joints and connections
Articulated members
Lockable at fixed position
4031093, 403104, F16B 710
Patent
active
06152638&
DESCRIPTION:
BRIEF SUMMARY
This invention relates to an extendable leg for a stand or similar appliance and is particularly although not exclusively applicable to a stand in the form of a tripod for mounting a camera or similar optical equipment.
A number of different forms of extendable leg are known for camera tripods and the like. Such legs have a plurality of extensions, each one locked and released by separate controls at spaced locations down the leg. This is inconvenient since each extension of each leg has to be re-locked separately which can be difficult for the camera operator to do, particularly in the case of a relatively heavy camera.
GB-A-1260368 discloses a leg for a photographic stand which is adjustable in length, the leg having a lower tubular member mounted for axial movement within an upper, outer tubular member to vary the length of the leg. A clamping device holds the lower member in a variety of desired positions along the leg axis, the clamping device being released from an upper part of the stand via a push-rod extending between the tubular members.
The object of the present invention is to provide an extendible leg consisting of at least three members with an arrangement for ensuring that one member is fully extended before the next member extends and, likewise, in retraction.
This invention provides an extendable leg for a stand or similar appliance having a plurality of elongate members interconnected to extend and retract with respect to each other including a first member at least one intermediate member and a final member, the intermediate member have a first releasable locking device adjacent to one end of the leg engagable with the first member and remote release means for releasing the first locking device from the other end of the leg to permit, when released, the first member to extend with respect to the intermediate member; wherein the final member has a second releasable locking device adjacent to said in one end of the leg engagable with the intermediate member and remote release means for releasing the second locking device from said other end of the leg; and in that additional locking means are provided between the intermediate and final members arranged to be released automatically on full extension of the first member with respect to the intermediate member to release the intermediate member for full extension with respect to the final member for full extension of the leg and to re-engage automatically on completion of retraction of the intermediate member with respect to the final member.
Preferably the locking means comprises a latch mounted on the intermediate member at a location adjacent said other end of the leg and held in locking engagement with the final member by the first member when the latter is in its retracted position and released therefrom when the first member is in its extended position.
More specifically the latch may have a projection which is engagable in an aperture in the final member to lock the intermediate member to the final member.
Furthermore, the latch may have an abutment engagable with the first member when the latter is in its retracted condition and released from the first member when the latter is in its fully extended condition to allow the latch member to disengage from the final member.
In one particular arrangement in accordance with the invention, the latch member may be pivotally mounted on the intermediate member.
Preferably the releasable locking devices may be spring biased in the locking direction and the remote release members may comprise push members extending from the other end of the leg acting on the locking devices so that when the first member is fully extended with respect to the intermediate member and the intermediate member commences to extend with respect to the final member, the locking device disengages from its push member so that the spring means acting on the locking device locks the device to the first member to lock the first and intermediate members together and so that when the intermediate member reaches its fully extende
REFERENCES:
patent: 2455525 (1948-12-01), Schulz
patent: 2600735 (1952-06-01), Corneliussen et al.
patent: 4029279 (1977-06-01), Nakatani
patent: 4174900 (1979-11-01), Ina
patent: 4362415 (1982-12-01), Metz et al.
patent: 4793197 (1988-12-01), Petrovsky
patent: 5492430 (1996-02-01), Jones
patent: 5593239 (1997-01-01), Sallee
patent: 5660495 (1997-08-01), Atsukawa
Bochna David E.
Browne Lynne H.
Vitec Group PLC
LandOfFree
Extendable legs for stands or similar appliances does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Extendable legs for stands or similar appliances, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Extendable legs for stands or similar appliances will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1718188