EP1138856A1

EP1138856A1 - Cabinet with telescopic shelves

Info

Publication number: EP1138856A1
Application number: EP00302563A
Authority: EP
Inventors: Edward c/o Cannon Technologies Ltd. Reddicliffe
Original assignee: Cannon Technologies Ltd
Current assignee: Cannon Technologies Ltd
Priority date: 2000-03-28
Filing date: 2000-03-28
Publication date: 2001-10-04

Abstract

A cabinet (1) that has at least one telescopic shelf (2) and at least one leg (9) engageable with a floor on which the cabinet is positioned and movable between a retracted position and an extended position so as to project on the same side of the cabinet as the shelf, includes an interlock mechanism (3,5) connected between the leg and the shelf and arranged to prevent the shelf from being moved to the extended position before the leg has similarly been extended, and to prevent retraction of the leg before retraction of the shelf.

Description

The present invention relates to cabinets having telescopic shelves and, more particularly, to such cabinets with a mechanism to prevent tipping when heavily loaded telescopic shelves are extended from within the cabinet.
Filing cabinets and the like often have telescopic shelves which are heavily loaded with equipment such as files or electronic devices and it has long been recognized that mechanisms may be needed to prevent tipping of such cabinets when the shelf, which may be in the form of a drawer, is extended or opened.
Historically, this problem has been partially overcome by preventing multiple drawers from being opened at the same time, but depending upon the height of the cabinet, this may be ineffective, particularly if top drawers are heavily loaded. More recently therefore it has been known either to bolt the cabinet to a strong floor structure or else to fit a permanent, forwardly extending plinth to the cabinet base so as, effectively, to extend the footprint of the cabinet to maintain stability. However, it has been found that such plinths may cause a hazard to people walking past the cabinet, in the form of a tripping hazard. Therefore a further technique is known, namely to fit a telescopically sliding plinth which can be pulled out from the base of the cabinet before the telescopic shelves are extended. The plinth can then be pushed back into the closed position once the shelves are pushed into the retracted position. Unfortunately, however, injury from tipping cabinets may still occur if the user forgets to withdraw the plinth before extending the loaded telescopic shelf.
The present invention is aimed at overcoming this problem.
According to the present invention there is provided a cabinet having:
at least one telescopic shelf movable between a retracted position in which the shelf is located in the cabinet and an extended position in which the shelf projects at least partly outside the cabinet; and
at least one leg engageable with a floor on which the cabinet is positioned and movable between a retracted position and an extended position so as to project on the same side of the cabinet as the shelf; characterised by
an interlock mechanism connected between the leg and the shelf and arranged to prevent the shelf from being moved to the extended position before the leg has been extended, and to prevent retraction of the leg before retraction of the shelf.
The leg or legs may be either hinged or telescopic and, if telescopic, may form a plinth housed, in the retracted position, in the base of the cabinet and movable out of the front of the base into the extended position.
In order to prevent the shelf or shelves being extended out of the retracted position, one or more pivotable wings or flanges may be provided along a vertical front edge of the cabinet in a position to partially overlie the front of the shelf or shelves when they are retracted, the wing or flange being pivotable to an open position allowing extension of the telescopic shelf or shelves when the leg is extended.
An alternative to the pivoted wing or flange may be a bar vertically movable into engagement with the shelf or shelves to prevent their extension and operable by movement of the leg.
The hinged wing or flange, or the vertically movable bar or rod may be interconnected to the plinth in a number of different ways.
In one example, the leg may be in the form of a telescopic plinth, as mentioned above, the plinth having a sloping flange engaging a pin which is retractable from a position in which it prevents opening of the wing or flange or else prevents a disengaging movement of the alternative bar from each of the shelves, by forward movement of the plinth causing the pin, following the slope of the flange (downwardly from front to back of the plinth) so that when the plinth is fully extended the pin is withdrawn to a position which allows the wing or flange or the vertically moving bar to move, in turn to allow opening of the telescopic shelf or shelves. In such a case, in order to prevent the plinth from being pushed back into its retracted position while the shelves are still extended, an abutment, possibly in the form of an additional flange, on the bottom of the wing or flange or the vertical bar, can be provided to block the movement of the pin engaged with the plinth.
The wing or flange may, of course, if desired, provide a door to the cabinet.
To prevent the possibility of the plinth being left in the extended position, the interlock mechanism may be constructed so as to cause the plinth to be retracted as the hinged wing is closed over the front of the shelves.
In other examples, the leg or legs may be hinged and the interlock mechanism may include a pivot pin (which might have cranked arms) which engages with the wing and the leg so as to cause them to be moved together.
The interlock mechanism may alternatively include cranked arms which hold the wings closed until a telescopic leg has been extended to the safe position, at which point the cranked arm is free to allow rotation of the wing or flange.
In a still further embodiment, a cable or chain actuated interlock mechanism may be provided, the cable or chain being routed around elements within the cabinet and connected between movable bars or front closing wings or flanges and the leg/plinth.
The cabinet may store electronic equipment, such as devices for use in the telecommunications industry.
A number of examples of cabinets constructed in accordance with the present invention will now be described with reference to the accompanying diagrammatic drawings in which:
Figure 1 is a perspective view, from one side, above and the front of a first cabinet;
Figure 2 is a broken vertical section through the cabinet from front to back, showing, in the upper half, a retracted shelf and closing pivoted wing and, in the lower half, an extended telescopic shelf and opened pivoted wing;
Figure 3 is a horizontal section through the cabinet showing one wing in an open position and one wing in a closed position.
Figure 4 is a section through the bottom of the cabinet showing a telescopic plinth and interlock mechanism;
Figure 5 is a view similar to figure 4 showing the plinth extended;
Figure 6 shows an alternative plinth construction; and,
Figures 7 and 8 show another cabinet construction having hinged legs.
The cabinet 1 shown in figures 1 to 5 may be a conventional filing cabinet or similar having telescopic shelves or drawers 2 arranged one above another at any height within the cabinet. In this example, a pair of vertically pivoted or hinged wings or flanges 3 are provided at the open front of the cabinet, one on each side, the wings or flanges 3 being pivotally mounted by appropriate pivot pins 4 at the top and bottom.
An interlock mechanism in the form of a retractable pin 5 sliding through a hole 6 in the base 7 of the cabinet is located, so as to prevent each of the wings 3 from opening, by connection to a sloping flange or the like 8 (see figures 4 and 5) disposed on a telescopic leg 9 in the form of a plinth housed in the base 7 of the cabinet.
As the plinth or leg 9 is moved forwards the slope on the flange 8 allows the pin 5 to retract to a lower position as seen in figure 5, in turn allowing the corresponding wing 3 to be opened and the shelf or shelves 2 to be extended.
At the lower edge of each wing 3 a horizontal additional flange or similar (not shown) may be provided to cover the opening 6 through which the interlock pin 5 moves, thus preventing the plinth from being retracted until the wings 3 have been closed. Since the wings 3 cannot be closed while the shelves are extended this prevents the plinth 9 from being retracted while the shelves are extended.
Figure 6 shows a second example, diagrammatically, in which the plinth or leg 9, which is again telescopically extendable at the base 7 of the cabinet 1, has a side member 11 with a cutout 10. In this case, the wings 3 each have a pivot rod 4 which includes a cranked portion 12. The pivot pin 4 is fixed onto the wing 3 in such a position that the cranked element 12 is substantially aligned with the side member 11 of the plinth 9 when the wing is in the closed position and is thus prevented from being moved out of this position until the plinth 9 has been extended to the point when the cutout 10 comes to lie adjacent the cranked element 12 of the pivot pin 4, at which point it may be rotated and hence the wing 3 rotated with it. Similarly, the plinth 4 cannot be pushed back to the retracted position without causing closure of the wing 3 and hence requiring the shelves to be retracted first.
Figures 7 and 8 show a third example of cabinet in which a pair of pivoting legs 9 are provided in the base 7 of the cabinet, pivotable between closed positions within the base 7 (see figure 8) and an open position (see right hand half of figure 7) in which they extend forwardly of the cabinet. The pivot pins 4 on which the legs 9 are pivotable also provide the lower pivots for the wings 3 and the pins 4 are fixed to both the legs 9 and wings 3 so that they open and close together.
It will be appreciated that many variations of leg movement, shelf restraint and interlock construction are possible within the concept of the present invention.

Claims

A cabinet (1) having:

at least one telescopic shelf (2) movable between a retracted position in which the shelf is located in the cabinet and an extended position in which the shelf projects at least partly outside the cabinet; and

at least one leg (9) engageable with a floor on which the cabinet is positioned and movable between a retracted position and an extended position so as to project on the same side of the cabinet as the shelf; characterised by

an interlock mechanism (3,5) connected between the leg (9) and the shelf (2) and arranged to prevent the shelf from being moved to the extended position before the leg has been extended, and to prevent retraction of the leg before retraction of the shelf.
A cabinet (1) according to claim 1, wherein the leg or legs (9) are hinged.
A cabinet (1) according to claim 1, wherein the leg or legs (9) are telescopic.
A cabinet (1) according to claim 3, wherein the leg or legs (9) form a plinth housed, in the retracted position, in the base (7) of the cabinet and movable out of the front of the base into the extended position.
A cabinet (1) according to any of claims 1 to 4, wherein one or more pivotable wings or flanges (3) are provided along a vertical front edge of the cabinet in a position to partially overlie the front of the shelf or shelves (2) when they are retracted, the wing or flange being pivotable to an open position allowing extension of the telescopic shelf or shelves when the leg (9) is extended.
A cabinet (1) according to any of claims 1 to 4, wherein the interlock mechanism includes a bar vertically movable into engagement with the shelf or shelves (2) to prevent their extension and operable by movement of the leg.
A cabinet (1) according to claim 3, wherein the leg (9) has a sloping flange (8) engaging a pin (5) which is retractable, from a position in which it prevents extension of the shelf or shelves (2), by forward movement of the leg causing the pin, following the slope of a flange on the leg as the leg is extended.
A cabinet (1) according to claim 7, wherein, in order to prevent the leg (9) from being pushed back into its retracted position while the shelves (2) are still extended, an abutment is moved to block the return movement of the pin engaged with the plinth until the shelf or shelves have been retracted.
A cabinet (1) according to claim 5, wherein the wing or flange (3) provides a door to the cabinet.
A cabinet (1) according to claim 5 or claim 9, wherein, to prevent the possibility of the leg (9) being left in the extended position, the interlock mechanism is constructed so as to cause the leg to be retracted as the wing is closed over the front of the shelves (2).
A cabinet (1) according to claim 2 and claim 5, wherein the interlock mechanism includes a pivot pin (4) which engages with the wing (3) and the leg (9) so as to cause them to be moved together.
A cabinet (1) according to claim 3 and claim 5, wherein the interlock mechanism includes a cranked arm (4,12) which holds the wing (3) closed until the telescopic leg (9) has been moved to the extended position, at which point the cranked arm is free to allow rotation of the wing.
A cabinet (1) according to claim 1, wherein a cable or chain actuated interlock mechanism is provided, the cable or chain being routed around elements within the cabinet and connected between movable bars or front closing wings and the leg/plinth.