Foldable pawl and ratchet assembly

Abstract

A ratchet device for a rocking furniture member has a plurality of structural elements. The ratchet device temporarily retains the furniture member in multiple engaged positions and includes: a pawl assembly having a pawl link rotatably connected to a first structural element; a plastic pawl lever rotatably connected to the pawl link; a first biasing element positioned between the pawl link and the pawl lever which biases the pawl lever toward a contact position with the pawl link; and a U-shaped bracket rotatably coupled to the pawl link and fixed to the first structural element. A ratchet having engagement teeth is fixed to a second structural element and located with the engagement teeth in a rotational path of the pawl lever. A second biasing element connected between the pawl link and the U-shaped bracket biases the pawl lever to engage the ratchet teeth.

1 . A ratchet device for a furniture member having a plurality of structural elements, the ratchet device operable to temporarily retain the furniture member in each of a plurality of rotated engaged positions, the ratchet device comprising: 
 a pawl assembly including: 
 a pawl link rotatably connectable to a first one of the structural elements of the furniture member;  
 a pawl lever rotatably connectable to the pawl link and biased toward an over-center contact position with the pawl link; and  
   a ratchet assembly including a ratchet body having a plurality of engagement teeth, the ratchet assembly fixedly connectable to a second one of the structural elements and located to position the engagement teeth in a rotational path of the pawl lever upon rotation of the pawl link.    
     
     
         2 . The ratchet device of  claim 1 , further comprising a plurality of engaged positions each having the pawl lever engaged between proximate ones of the plurality of teeth, the pawl lever and the pawl link being positioned in the contact position in each of the engaged positions.  
     
     
         3 . The ratchet device of  claim 2 , further comprising: 
 a stowed position of the pawl assembly having the pawl lever disengaged from any of the teeth;    wherein the pawl link is rotatable about an arc of rotation defining a first direction toward the ratchet assembly from the stowed position to any of the plurality of engaged positions, and a second direction away from the ratchet assembly.    
     
     
         4 . The ratchet device of  claim 3 , 
 wherein the pawl lever is rotatable in the second direction to operably return the pawl lever and the pawl link from any of the plurality of engaged positions to the stowed position; and    wherein the pawl lever is rotatable about a second arc of rotation substantially toward the second direction with respect to the pawl link during disengagement of the pawl lever from the ratchet assembly.    
     
     
         5 . The ratchet device of  claim 1 , further comprising: 
 a bracket fastenably connectable to the first one of the structural elements of the furniture member and adapted to rotatably receive the pawl link; and    a pin operable to rotatably connect the pawl link to the bracket.    
     
     
         6 . The ratchet device of  claim 5 , further comprising a biasing element positioned in contact with both the pawl link and the bracket, the second biasing element operable to bias the pawl link toward the ratchet assembly.  
     
     
         7 . The ratchet device of  claim 1 , wherein the pawl lever further comprises: 
 a main body portion;    first and second walls positioned in opposition to each other about the main body portion, the walls each integrally connected to the main body portion and extending substantially perpendicular to the main body portion; and    a biasing element having a first portion positioned between the first and second walls and in contact with the main body portion.    
     
     
         8 . The ratchet device of  claim 7 , wherein the pawl link further comprises: 
 a main wall; and    first and second link walls positioned in opposition to each other about the main wall, the link walls each integrally connected to the main wall and extending substantially perpendicular to the main wall;    wherein a second portion of the biasing element is positioned between the first and second link walls and in contact with the main wall.    
     
     
         9 . The ratchet device of  claim 1 , wherein the pawl lever comprises a polymeric material.  
     
     
         10 . The ratchet device of  claim 9 , wherein the polymeric material further comprises a nylon material.  
     
     
         11 . The ratchet device of  claim 9 , wherein the pawl link comprises one of a metal and a polymeric material.  
     
     
         12 . The ratchet device of  claim 9 , wherein the ratchet comprises one of a metal and a polymeric material.  
     
     
         13 . The ratchet device of  claim 1 , further comprising a pin operable to rotatably connect the pawl lever to the pawl link.  
     
     
         14 . The ratchet device of  claim 1 , wherein the pawl lever further comprises a ratchet engaging end defining an apex, the apex further defining a clearance angle with a face of any of the engagement teeth, the clearance angle operable to limit contact between the ratchet engaging end and any of the engagement teeth.  
     
     
         15 . The ratchet device of  claim 1 , further comprising a biasing element in contact with both the pawl lever and the pawl link operable to bias the pawl lever toward the over-center contact position.  
     
     
         16 . The ratchet device of  claim 1 , wherein the over-center contact position defines a distance between: 
 a line extending from a center of rotation of the pawl link to a distal engagement end of the pawl lever; and    a center of rotation of the pawl link about the pawl lever.    
     
     
         17 . A ratchet device for a rocking furniture member having a plurality of structural elements, the ratchet device operable to temporarily retain the furniture member in each of a plurality of engaged positions, the ratchet device comprising: 
 a pawl assembly including: 
 a pawl link rotatably connectable to a first one of the structural elements of the furniture member;  
 a polymeric pawl lever rotatably connectable to the pawl link;  
 a first biasing element disposed between the pawl link and the pawl lever operable to bias the pawl lever toward a contact position with the pawl link; and  
 a substantially U-shaped bracket rotatably coupled to the pawl link and fixedly connected to one of the structural elements;  
   a ratchet assembly having a plurality of engagement teeth, the ratchet assembly fixedly connectable to a second one of the structural elements and located to position the engagement teeth in a rotational path of the pawl lever upon rotation of the pawl link; and    a second biasing element connected between the pawl link and the U-shaped bracket operable to bias the pawl lever toward the ratchet assembly.    
     
     
         18 . The ratchet device of  claim 17 , further comprising a first pin rotatably coupling the pawl lever to the pawl link.  
     
     
         19 . The ratchet device of  claim 18 , wherein the pawl lever further comprises a main body portion having integral opposing walls extending substantially perpendicular to the main body portion, each of the opposing walls having an aperture adapted to receive the first pin.  
     
     
         20 . The ratchet device of  claim 19 , further comprising a second pin rotatably coupling the pawl link to the bracket.  
     
     
         21 . The ratchet device of  claim 17 , wherein the pawl link further comprises a main wall having integral opposing link walls extending substantially perpendicular to the main wall, each of the opposing link walls having a through aperture adapted to receive the second pin.  
     
     
         22 . The ratchet device of  claim 21 , wherein the pawl link further comprises a hook positioned in the main wall, the hook adapted to receive a drive link operable to rotate the pawl link about the second pin both toward and away from the ratchet assembly.  
     
     
         23 . The ratchet device of  claim 17 , wherein the polymeric pawl lever further comprises a nylon material.  
     
     
         24 . The ratchet device of  claim 17 , wherein the U-shaped bracket further comprises a raised element operable as a rotational stop for the pawl link.  
     
     
         25 . A furniture member leg rest mechanism connectable to both a furniture member structure and a seat frame, the leg rest mechanism comprising: 
 a drive mechanism including a drive rod for rotational movement in a first and second direction;    an actuator for permitting a seat occupant to selectively actuate the drive mechanism;    a ratchet having a plurality of ratchet teeth formed thereon;    a pawl assembly, including: 
 a pawl link having a first end pivotally connectable to the frame for rotational movement of the pawl link between a first position and a second position, and a second end;  
 a pawl lever pivotally coupled to the second end of the pawl link, the pawl lever lockingly engaging the ratchet teeth in the first position wherein the frame is releasably locked in a rearwardly tilted position, and a second position released from the ratchet teeth for permitting unrestricted rocking movement of the seat frame.  
   
     
     
         26 . The leg rest mechanism of  claim 25 , further comprising: 
 a release assembly including a swivel link supported on the drive rod for free rotation thereabout; and    a rigid drive link having a first end coupled to the pawl link and a second end pivotally connected to the swivel link;    wherein the pawl link further comprises a hook formed thereon for engaging the release link to couple said release assembly to said pawl link.    
     
     
         27 . The leg rest mechanism of  claim 26 , wherein the pawl lever is substantially U-shaped in cross section having a main body portion and a pair of laterally extending walls, the main body portion having a ratchet engaging end defining an axis for engaging the ratchet, and each of the walls having an aperture therethrough for pivotally coupling the pawl lever to the pawl link.  
     
     
         28 . The leg rest mechanism of  claim 25 , further comprising a substantially U-shaped bracket having a first portion secured to the structure and a pair of laterally spaced legs for receiving the pawl link therebetween, each of the legs having an aperture therethrough for receiving a pin to pivotally couple the pawl link to the bracket.  
     
     
         29 . The leg rest mechanism of  claim 25 , further comprising a biasing element for normally biasing the pawl link toward the first position, the biasing element adapted to exert an engagement force on the pawl link for maintaining locked engagement of the pawl lever with the ratchet teeth when the pawl link is in the first position.  
     
     
         30 . A ratchet device for a furniture member, the furniture member including a plurality of structural elements, the ratchet device comprising: 
 a pawl assembly including: 
 a pawl link rotatably connectable to a first one of the structural elements of the furniture member;  
 a pawl lever rotatably connectable to the pawl link, the pawl lever including an engagement end having a substantially rounded surface; and  
 a biasing element operable to bias the pawl lever toward an over-center contact position with the pawl link; and  
   a ratchet assembly including a ratchet body having a plurality of engagement teeth, the ratchet assembly fixedly connectable to a second one of the structural elements and located to position the engagement teeth in a rotational path of the pawl lever upon rotation of the pawl link;    a plurality of engaged positions between the engagement end of the pawl lever and adjacent pairs of the engagement teeth, the ratchet device operable to temporarily retain the furniture member in each of a plurality of rotated engaged positions having the pawl lever in the over-center contact position; and    a release path defined when the pawl link is rotated about the rotational path away from ratchet assembly, the pawl lever being rotatably released from the over-center contact position and the substantially rounded surface operable to release the pawl lever in a folding motion from the engagement teeth.    
     
     
         31 . The ratchet device of  claim 30 , wherein the pawl lever comprises a polymeric material.  
     
     
         32 . The ratchet device of  claim 30 , further comprising a pin operable to rotatably connect the pawl lever to the pawl link.  
     
     
         33 . The ratchet device of  claim 30 , further comprising a second biasing element operable to bias the pawl link toward the ratchet assembly.  
     
     
         34 . The ratchet device of  claim 30 , further comprising a drive link connectable to the pawl link and operable to translate the pawl link about the release path.  
     
     
         35 . A method for creating a pawl and ratchet assembly operable to position a furniture member in each of a plurality of engagement positions, the pawl and ratchet assembly having a pawl lever, a pawl link, and a ratchet having a plurality of engagement teeth, the furniture member having a plurality of structural elements, the method comprising: 
 rotatably connecting the pawl link to one of the structural elements of the furniture member;    rotatably coupling the pawl lever to the pawl link;    engaging a biasing element with both the pawl lever and the pawl link operable to bias the pawl lever toward a contact position with the pawl link; and    fixedly connecting the ratchet assembly to a second one of the structural elements having the engagement teeth in alignment with in a rotational path of the pawl lever to operably permit the pawl lever to engage the engagement teeth.    
     
     
         36 . The method of  claim 35 , further comprising creating the pawl lever from a polymeric material.  
     
     
         37 . The method of  claim 35 , further comprising increasing a width of both the pawl lever and the engagement teeth to accommodate an occupant weight.  
     
     
         38 . The method of  claim 35 , further comprising increasing a width of both the pawl lever and the engagement teeth to decrease a ratcheting sound level of the pawl and ratchet assembly.