Mechanism for an extension leaf

Abstract

A mechanism for an extension leaf of an extension table. The mechanism comprises a frame defining a first formation configured for engagement by an end of a first axle of the extension leaf and second formation configured for engagement by an end of a second axle of the extension leaf. The first formation mounts the end of the first axle for rotation about a first axis that is parallel to a hinge axis of the extension leaf, and constrains the first axle against translation in a plane perpendicular to the first axis. In the illustrated embodiment, the first formation is simply an aperture in the frame. The second formation defines an elongate path along the frame, supports the end of the second axle for rotation about a second axis, and guides the second axle along the elongate path from end to end during reconfiguration of the extension leaf between its extended configuration and its collapsed configuration as shown. A force transfer component is hingedly connected to the frame about a third axis and defines an abutment surface extending across the elongate path for engagement by the end of the second axle during the movement of the second axle toward end of the elongate path. Rotation of the lever arm in a first direction about the third axis causes the abutment surface to move toward end of the path and rotation of the lever arm in an opposite, second direction about the third axis causes the abutment surface to move toward end of the path. A damper is connected to the force transfer component to damp force applied to it when it is engaged by the end of the second axle during the movement of the second axle toward end of the elongate path.

1 . A mechanism for an extension leaf, the mechanism comprising:
 a frame defining:
 a first formation configured for engagement by an end of a first axle of the extension leaf to mount the end of the first axle for rotation about a first axis and constrain the first axle against translation in a plane perpendicular to the first axis, and 
 a second formation defining an elongate path along the frame, the second formation being configured for engagement by an end of a second axle of the extension leaf to support the end of the second axle for rotation about a second axis and during movement of the second axle along the elongate path, a first end of the path being associated with the position of the end of the second axle when the extension leaf is in an extended configuration and an opposite, second end of the path being associated with the position of the end of the second axle when the extension leaf is in a collapsed configuration; 
   a force transfer component hingedly connected to the frame about a third axis and defining an abutment surface extending across the elongate path in the frame, rotation of the force transfer component in a first direction about the third axis causing the abutment surface to move toward the first end of the path and rotation of the force transfer component in an opposite, second direction about the third axis causing the abutment surface to move toward the second end of the path, the abutment surface being configured for engagement by the end of the second axle during the movement of the second axle toward the second end of the elongate path; and   a damper connected to the force transfer component to damp force applied to the force transfer component by the end of the second axle during the movement of the second axle toward the second end of the elongate path.   
     
     
         2 . The mechanism of  claim 1 , wherein the damper is a linear damper having a first end hingedly connected to the frame for rotation about a fourth axis and an opposite, second end connected to the force transfer component. 
     
     
         3 . The mechanism of  claim 2 , wherein the second end of the damper is connected to the force transfer component at a location between the third axis and the abutment surface. 
     
     
         4 . The mechanism of  claim 2 , wherein the second end of the linear damper is hingedly connected to the force transfer component. 
     
     
         5 . The mechanism of  claim 2 , wherein the distance between the fourth axis and the connection between the second end of the damper and the force transfer component gradually reduces or gradually increases during rotation of the force transfer component between a first orientation in which it extends across the elongate path at a first location along the elongate path and a second orientation in which it extends across the elongate path at the second end of the elongate path, the first location along the elongate path being between the midpoint of the elongate path and the second end of the elongate path, the gradual reduction or gradual increase in the distance actuating the linear damper via respective compression or extension thereof. 
     
     
         6 . The mechanism of  claim 5 , wherein the distance between the fourth axis and the connection between the second end of the damper and the force transfer component gradually reduces or gradually increases by less than 80 percent during the rotation of the force transfer component between the first orientation and the second orientation. 
     
     
         7 . The mechanism of  claim 5 , wherein the distance between the fourth axis and the connection between the second end of the damper and the force transfer component gradually reduces or gradually increases by less than 60 percent during the rotation of the force transfer component between the first orientation and the second orientation. 
     
     
         8 . The mechanism of  claim 5 , wherein the distance between the fourth axis and the connection between the second end of the damper and the force transfer component gradually reduces or gradually increases by less than 50 percent during the rotation of the force transfer component between the first orientation and the second orientation. 
     
     
         9 . The mechanism of  claim 5 , wherein the distance between the fourth axis and the connection between the second end of the damper and the force transfer component gradually reduces or gradually increases by less than 60 mm during the rotation of the force transfer component between the first orientation and the second orientation. 
     
     
         10 . The mechanism of  claim 5 , wherein the distance between the fourth axis and the connection between the second end of the damper and the force transfer component gradually reduces or gradually increases by less than 50 mm during the rotation of the force transfer component between the first orientation and the second orientation. 
     
     
         11 . The mechanism of  claim 5 , wherein the distance between the fourth axis and the connection between the second end of the damper and the force transfer component gradually reduces or gradually increases by less than 35 mm during the rotation of the force transfer component between the first orientation and the second orientation. 
     
     
         12 . The mechanism of  claim 1 , wherein the damper is configured to damp the force applied to the force transfer component by the end of the second axle during the movement of the second axle toward the second end of the elongate path from a first location along the elongate path to the second end of the elongate path, the first location along the elongate path being between the midpoint of the elongate path and the second end of the elongate path. 
     
     
         13 . The mechanism of  claim 5 , wherein the damper is configured to apply an assistive force to the force transfer component during the movement of the second axle along the elongate path from the second end to the first location along the elongate path. 
     
     
         14 . The mechanism of  claim 1 , wherein the force transfer component is a lever arm. 
     
     
         15 . An extension leaf comprising the mechanism of  claim 1 . 
     
     
         16 . An extension table comprising at least one said extension leaf according to  claim 15 .