Patent Application
20050040659
This invention relates to locking mechanisms for furniture items having multiple drawers.
Locking mechanisms are known which prevent the opening of more than one drawer in a filing cabinet at any one time. This is to prevent the possibility of the cabinet over-balancing and toppling forward. Such mechanisms typically comprise a series of latching devices which are controlled by an actuator upon opening movement of one drawer to block opening movement of the other drawers. There is an increasing need for such locking mechanisms to be fitted to other items of furniture which feature multiple drawers, such as desks or chests of drawers. Difficulties arise when designing such locking mechanisms to operate on drawer systems which cater for different size drawers or which allow for adjustable positioning of their drawers.
The invention provides a locking mechanism for an item of furniture having two or more drawers and means mounting the drawers for openable and closable movement, in which each drawer has associated with it a latching device co-operable with the furniture item to allow opening movement of the drawer in a first position of the latching device and to prevent said opening movement in a second position of the latching device, there being a connecting member linking together the latching devices of all the drawers such that opening of any one of the drawers causes the latching devices of all the other drawers to move to their second position, whilst closure of said one drawer causes the latching devices of all the other drawers to return to their first position, wherein the latching devices are connectable to said connecting member at positions to be determined by reference to fixed points on the furniture item for the drawer mounting means.
The invention also includes a method of assembling a drawer locking device for an item of furniture comprising a plurality of drawers, said drawer locking device comprising respective blocking devices for blocking movement of said plurality of drawers and a connector for connecting said blocking devices such that movement of any one of said plurality of blocking devices caused by opening of the respective drawer causes a corresponding movement of each of the remaining said blocking devices to respective positions in which opening of the respective drawers is blocked, said method comprising connecting said blocking devices with said furniture item at respective reference positions provided in said furniture item, fixing said connector to said blocking devices when said blocking devices are connected with said furniture item at said respective reference positions to provide a drawer locking device in which said blocking devices are fixed to said connector at spaced apart positions determined by said reference positions and disconnecting said drawer locking device from said item of furniture for fitting to said item of furniture in an operative position.
The invention also includes a drawer locking device for an item of furniture having a plurality of drawers, said locking device comprising a plurality of blocking devices each of which, in use, is movable between a first position permitting opening of a respective drawer and a second position in which opening of the respective drawer is blocked, and a connecting member for connecting said blocking devices such that movement of any one of the blocking device causes a similar movement of each other blocking device, said blocking devices each having a first connecting portion for releasable connection with respective reference connections associated with each drawer in said furniture item and a second connecting portion for connection with said connecting member, the arrangement being such that said connecting member can be connected to said second connecting portions of said blocking devices when said blocking devices are connected with said reference connections by said first connecting portions whereby said blocking devices are connected to said connecting member with a spacing substantially determined by said reference connections.
By way of example, an embodiment of the invention will now be described with reference to the accompanying drawings, in which:
a and 3b shows the design of the latching device of the
a and 5b are diagrammatic illustrations showing how the pin members and latching devices co-operate in use.
The inside faces of the cabinet and the outside faces of the drawer sides are pre-drilled with a standard pattern of holes for attaching the drawer runners, usually by means of screws. These hole patterns ensure that when the cabinet is assembled, typically by the consumer at home, the runners are set at the correct spacing and alignment for the drawers.
The cabinet seen in
The latching devices 13a, 13b, 13c, 13d are engagable by pins associated with each respective drawer (only pin 16c is seen in
One of the difficulties when designing locking mechanisms of this nature is to enable them easily to be adapted to be used with different numbers, sizes and configurations of drawer systems, whilst still remaining relatively simple to assemble and reliable in use. To that end, the connecting member 14 here has been designed as an extruded plastics track to which the latching devices 13 can be fitted by hand with a simple snap action. By this means, the particular number and spacing of latching devices on the connecting member can be tailored to any number of different settings, suiting a wide range of different furniture applications.
As seen in
a and 3b show in more detail the design of the connecting member 14 and latching device 13.
As seen in
As seen in
The main body of the latching device 13 contains a contoured guideway 22 for slidable receipt of the pin 16 connected to its associated drawer 11. As will be seen, the guideway 22 has an entrance 23 below an angled face 24 of the body. From the entrance 23, the guideway 22 extends upwardly at an acute angle to a backward position 25, from which it then extends downwardly to a pocket 26. The wall of the guideway 22 just above the pocket 26 is formed with a spring finger 27, with a small rounded protrusion 28 extending into the guideway. When the latching device 13 is moved upwardly relative to its associated pin 16, the pin moves into the pocket 26, resiliently biasing the spring finger 27 on its way as it does so. The spring finger 27 returns to its original position when the pin 16 sits in the pocket 26, thereby holding the pin in that position. This is enough to hold the connecting member 14, with all the latching devices 13 attached, in its blocking position, i.e. preventing it from falling back to its unblocking position under gravity.
The body of the latching device 13 also features a spacer 29. The purpose of this spacer 29 is to pick up on the runner 12 of the drawer 11 and thereby distance the latching device 13 by the appropriate amount from this level. This sets the latching device 13, and in particular the entrance 23 to its guideway 22, at the correct level to engage its associated pin 16.
The pin 16 for each drawer 11 may simply take the form of a dowel or peg fitted in a suitable hole pre-drilled in the side of the drawer. With such arrangements, the exact position of the pins is governed by the pre-drilling and the latching device can be designed accordingly so as to engage it properly. Nowadays, however, drawer runners have come on to the market which allow for some vertical adjustment of the drawer relative to its runners. With such arrangements, it may no longer be appropriate to use pins that are fixed to the drawers, because their exact position relative to the cabinet may vary, in some instances by more than an allowable tolerance, with the result that the locking mechanism will not work properly. As an alternative, therefore, as seen in
As seen in
a and 5b illustrate schematically how the pins 16a, 16b of two drawers co-operate with their associated latching devices 13a, 13b.
When the upper drawer is closed again, it will be seen that its associated pin 16a will move in a direction opposite to arrow A and strike the opposite ramped surface 34b of the guideway 22a of its associated latching device 13a, causing the latching device to move downwardly again, together with, via the connecting member 14, the lower latching device 13b. The locking mechanism thus returns to the position shown in
If desired, the furniture item may include means operable by a key for locking all the drawers. This would operate simply to move the connecting member upwardly so that each pin is seated in the pocket of its associated latching element, thereby blocking movement of all the pins and their associated drawers.
It will be appreciated that the drawer locking mechanism is intended primarily for use in knock-down furniture and the process of fitting the latching devices to the connecting member will normally take place prior to assembly of the furniture item using a component of the furniture item that has been provided with fixing holes for the drawer runners. Preferably the actual fixing holes will be used for locating the latching devices while the connecting member is connected to them. However, it is possible, although not preferred, to provide dedicated reference holes at predetermined distances from the fixing holes.
It is to be understood that numerous variations and modifications to the preferred embodiments of the invention may be made by those skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.
