Spring actuated rocking mechanism for collapsible chair

Abstract

A spring actuated rocking mechanism can be attached to the legs of a collapsible chair to allow for the user to rock in the collapsible chair. The mechanism may be attached at the factory or retrofitted to the chair. The rocking mechanism can be attached to the end of a leg or disposed within a leg, having a leg portion above and below the mechanism.

I claim: 
     
         1 . A rocking mechanism to attach to a single leg of a collapsible chair comprising:
 a tubular housing having an interior portion extending between an upper end and a lower end;   an upper cap fixedly attached to the tubular housing at the upper end, the cap configured to engage the single leg of the collapsible chair;   a lower cap fixedly attached to the tubular housing at the lower end and having an opening therethrough to receive a second leg portion that extends into the interior portion of the tubular housing;   a plunger disposed within the interior portion of the tubular housing, the plunger connectable to the second leg portion and having a plurality of rollers disposed about a periphery of the plunger to engage an inside surface of the tubular housing; and   a spring disposed in the interior portion of the tubular housing between the upper cap and the lower cap.   
     
     
         2 . The rocking mechanism according to  claim 1 , wherein the plunger has a base with a flat upper surface, a lower surface having a cylindrical extension extending downward therefrom and a plurality of tabs extending from the cylindrical extension creating a plurality of spaces to receive the plurality of rollers. 
     
     
         3 . The rocking mechanism according to  claim 2 , wherein each of the plurality of tabs have a hole to receive a roller pin. 
     
     
         4 . The rocking mechanism according to  claim 2 , wherein the plurality of rollers are mounted on a wire and each of the plurality of tabs have a slot to receive a portion of the wire therein. 
     
     
         5 . The rocking mechanism according to  claim 2 , wherein the tabs are connected to the lower surface of the plunger. 
     
     
         6 . The rocking mechanism according to  claim 2 , wherein the spring engages the upper surface of the plunger and the upper cap. 
     
     
         7 . The rocking mechanism according to  claim 2 , wherein the rollers extend radially outward beyond an edge of the flat upper surface. 
     
     
         8 . The rocking mechanism according to  claim 2 , wherein the cylindrical extension of the plunger is configured to receive the second leg therein. 
     
     
         9 . The rocking mechanism according to  claim 1 , wherein the second leg portion includes a foot at an end thereof that is opposite to an end engaging the cylindrical extension of the plunger. 
     
     
         10 . The rocking mechanism according to  claim 2 , wherein the spring is under constant compression between the upper and lower caps. 
     
     
         11 . The rocking mechanism according to  claim 1 , wherein the plunger has a base with a flat upper surface, a lower surface having a cylindrical extension extending downward therefrom and a groove extending around a periphery of the base, the groove having a plurality of ball bearings disposed within the groove. 
     
     
         12 . A plunger for a rocking mechanism comprising:
 a base;   a flat upper surface on one side of the base;   a lower surface on a second side of the base;   a cylindrical extension extending downward from the second side;   a plurality of tabs extending from the cylindrical extension creating a plurality of spaces; and   a plurality of rollers, each of the plurality of rollers disposed in between two of the plurality of tabs.   
     
     
         13 . The plunger for a rocking mechanism according to  claim 2 , wherein each of the plurality of tabs have a hole to receive a roller pin. 
     
     
         14 . The plunger for a rocking mechanism according to  claim 2 , wherein the plurality of rollers are mounted on a wire and each of the plurality of tabs have a slot to receive a portion of the wire therein. 
     
     
         15 . The plunger for a rocking mechanism according to  claim 2 , wherein the tabs are connected to the lower surface of the plunger. 
     
     
         16 . The plunger for a rocking mechanism according to  claim 2 , wherein the spring engages the upper surface of the plunger and the upper cap. 
     
     
         17 . The plunger for a rocking mechanism according to  claim 2 , wherein the rollers extend radially outward beyond an edge of the flat upper surface. 
     
     
         18 . A plunger for a rocking mechanism comprising:
 a base;   a flat upper surface on one side of the base;   a lower surface on a second side of the base,   a cylindrical extension extending downward from the second side; and   at least one groove extending around a periphery of the base, the at least one groove having a plurality of ball bearings disposed within the groove.   
     
     
         19 . The plunger for a rocking mechanism according to  claim 18 , wherein the base has at least one cavity extending into a middle portion of the base from one of the flat upper surface and the lower surface. 
     
     
         20 . The plunger for a rocking mechanism according to  claim 18 , wherein the at least one groove comprises two grooves.