Pad plunger

Abstract

Embodiments of the present invention relate to an improved pad plunger. The improved pad plunger may include a first biasing force, such as a first spring with a first rating, on a pad of the pad plunger and a second biasing force, such as a second spring with a second rating, on another pad of the pad plunger. The biasing forces exerted on the pads of the pad plunger may be different, thereby resulting in a pad plunger having pads with different biasing forces exerted thereon.

1 . A pad plunger, comprising:
 a body; and   a plurality of pads biased to move relative to the body,   wherein at least a first one of the plurality of pads is biased to move relative to the body at one rate, and a second one of the plurality of pads is biased to move relative to the body at another rate.   
     
     
         2 . The pad plunger of  claim 1  wherein at least the first one of the plurality of pads or the second one of the plurality of pads is biased by a spring. 
     
     
         3 . The pad plunger of  claim 2  wherein the first one of the plurality of pads is biased by a first spring and the second one of the plurality of pads is biased by a second spring. 
     
     
         4 . The pad plunger of  claim 3  wherein the first spring has a first rate and the second spring has a second rate. 
     
     
         5 . The pad plunger of  claim 4  wherein the first rate and the second rate are different. 
     
     
         6 . The pad plunger of  claim 5  wherein the first one of the plurality of pads is located toward a top end of the pad plunger. 
     
     
         7 . The pad plunger of  claim 6  wherein the second one of the plurality of pads is located toward a bottom end of the pad plunger. 
     
     
         8 . The pad plunger of  claim 7  wherein the first rate is greater than the second rate. 
     
     
         9 . The pad plunger of  claim 3  wherein the first spring has a first end and a second end, where the first end sits in a first pocket in the body and the second end sits in a pocket in the first one of the plurality of pads. 
     
     
         10 . The pad plunger of  claim 9  wherein the second spring has a first end and a second end, where the first end sits in a second pocket in the body and the second end sits in a pocket in the second one of the plurality of pads. 
     
     
         11 . The pad plunger of  claim 10  wherein the first pocket in the body and the pocket in the first one of the plurality of pads have a first collective depth. 
     
     
         12 . The pad plunger of  claim 11  wherein the second pocket in the body and the pocket in the second one of the plurality of pads have a second collective depth. 
     
     
         13 . The pad plunger of  claim 12  wherein the first collective depth and the second collective depth are the same. 
     
     
         14 . The pad plunger of  claim 13  wherein the first spring has a first rate and the second spring has a second rate. 
     
     
         15 . The pad plunger of  claim 14  wherein the first rate and the second rate are different. 
     
     
         16 . The pad plunger of  claim 15  wherein the first one of the plurality of pads is located toward a top end of the pad plunger. 
     
     
         17 . The pad plunger of  claim 16  wherein the second one of the plurality of pads is located toward a bottom end of the pad plunger. 
     
     
         18 . The pad plunger of  claim 17  wherein the first rate is greater than the second rate. 
     
     
         19 . The pad plunger of  claim 12  wherein the first collective depth and the second collective depth are different. 
     
     
         20 . The pad plunger of  claim 19  wherein the first collective depth is less than the second collective depth. 
     
     
         21 . The pad plunger of  claim 20  wherein the first spring has a first rate and the second spring has a second rate. 
     
     
         22 . The pad plunger of  claim 21  wherein the first rate and the second rate are the same. 
     
     
         23 . The pad plunger of  claim 22  wherein the first one of the plurality of pads is located toward a top end of the pad plunger. 
     
     
         24 . The pad plunger of  claim 23  wherein the second one of the plurality of pads is located toward a bottom end of the pad plunger.