GB2335459A

GB2335459A - Self-locking device for telescopic stands

Info

Publication number: GB2335459A
Application number: GB9805706A
Authority: GB
Inventors: Anthony Dew Armond
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-03-18
Filing date: 1998-03-18
Publication date: 1999-09-22
Also published as: GB9805706D0

Abstract

Hinged flanges 1, attached to sections of the telescopic legs of tripods and other stands, lack the sections relative to each other when the legs are at the necessary extended length, without requiring any attention from the user. The grip of the flanges can be released by inverting the stand and slightly further extending the legs.

Description

1 SELF-LOCKING DEVICE FOR TELESCOPIC STANDS 2335459 This device locks all

sections of telescopic legs of tripods and other stands simultaneously at the correct extension without attention by the user.

Generally, existing stands (usually supporting optical equipment) require manual release, extension and locking of each section of each leg according to the height of the user and irregularity of the ground, by which time the subject being observed, photographed or filmed may well have moved disadvantageously.

The self-locking device allows the user to keep both hands on the optical apparatus and the eye at the viewfinder whilst the stand becomes rapidly locked firmly at a comfortable height despite uneven terrain or on steps.

On extension of each leg, the sections slide along one another until reaching an inbuilt restraint or until the ground is struck. At this point, hard-edged flanges, hinged to one section, grip the adjacent section. The grip is initiated by the momentum of the flanges and strengthened and maintained by the weight of the apparatus being supported.

A simple mechanism not covered by this patent spreads the legs and allows them to extend by gravity, being triggered without the user having to let go of the optical apparatus with either hand.

When retracting the legs of a conventional tripod or stand, usually each segment of each leg has to be unlocked, pushed upwards and relocked, which requires 27 actions in a tripod whose legs have 4 sections, or 9 actions if the tripod is first turned upside down. With the new devices fitted, after inverting the tripod, the legs will fully retract if each is further extended by hand, to release the grip of the flanges, this procedure requiring 3 actions. The legs are held retracted and folded together by the mechanism mentioned above which is not covered by this patent.

FIGURE 1 shows the device adapted to fit inside the tubular telescopic legs of common tripods.

FIGURE 2 shows how the device can be adapted to work in stands where the outer tubular sections are designed to descend below the inner sections.

2 FIGURE 3 shows the principle adapted to legs of f lat or angular crosssection.

Figure 1 shows the principle of the device to be patented, although details of construction may be varied, and the principle can be applied to a variety of situations, yet still covered by this patent, as in Figures 2 and 3 for example.

The pair of flanges' are hinged across the diameter of the inner cylindrical segment' whose sides are modified to give support to the pivotal pin'. When descent of the inner cylinder is halted, the flanges are spread by their momentum and their outer corners grip the outer cylinder' which becomes weightbearing and locks the grip.

The flanges are prevented from spreading to 1800 with respect to each other by, in this example, the top rim of the inner cylinder, otherwise the mechanism will not perform as specified. In this illustration, self tapping screws' are inserted into the centre of each flange so that their heads would abut and prevent either flange from reaching a vertical position. 3 mm of "give" built into the restraint (which prevents one section from sliding completely out of the end of the other) would facilitate releasing the grip of the flanges.

Figure 2 is a cross section of the arrangement when the outer segment is to extend below the inner one. The numbers ref er to the same parts as in Figure 1, with the addition of the two counterweights' which weigh about twice that of their diametrically opposite counterpart flanges.

Figure 3 is an example of the f langes attached to right-angled sections, there being no limit to the potential for robustness of construction, and extra steel flanges could be hinged one above the other upon stout brackets. Note the pins' which restrict movement of the flanges according to the principles in the description of Figure 1.

aAIMS -7 1. Hinged flanges, attached to sections of the telescopic legs of stands, lock the sections at the required degree of extension without action by the user.

Claims

2. The hinged f langes of Claim 1 have restraints to their range of

movement.

3. The hinged flanges of Claims 1 and 2, when attached to the lower end of sections, have extensions beyond the hinges which more than counterbalance the weight of the flanges.