Anti-kickback insertable chain and replaceable teeth therefor

Abstract

An anti-kickback saw chain including a plurality of links each having an upstream end and a downstream end relative to a direction of travel of the chain is provided. The anti-kickback saw chain comprises a holding link having a first side and a second side, a replaceable tooth adapted to be removably mounted on the downstream end of the holding link, and a safety drive link. The upstream end of the safety drive link is pivotally connected to the downstream end of the first side of the holding link. The safety drive link includes a safety lobe effective to prevent the tooth from being dislodged from the holding link during chain travel, and a substantially flat upper edge.

1 . An anti-kickback saw chain including a plurality of links each having an upstream end and a downstream end relative to a direction of travel of the chain comprising:
 a holding link having a first side and a second side;   a replaceable tooth adapted to be removably mounted on the downstream end of said holding link; and   a safety drive link, wherein said upstream end of said safety drive link is pivotally connected to the downstream end of the first side of said holding link, said safety drive link including a safety lobe effective to prevent said tooth from being dislodged from said holding link during chain travel, and a substantially flat upper edge.   
     
     
         2 . The anti-kickback saw chain of  claim 1 , wherein said safety lobe is disposed near said downstream end of said safety drive link. 
     
     
         3 . The anti-kickback saw chain of  claim 1 , wherein said flat upper edge is adapted to decrease the range of motion and limit rollback movement of the holding link. 
     
     
         4 . The anti-kickback saw chain of  claim 1 , further including a tab extending outwardly from the first side of the downstream end of said holding link. 
     
     
         5 . The anti-kickback saw chain of  claim 4 , wherein said tab is positioned on said holding link to contact the top of said safety drive link and limit rollback movement by the holding link. 
     
     
         6 . The anti-kickback saw chain of  claim 1 , wherein said safety drive link includes an upstream and downstream rivet hole, said upstream rivet hold being generally semi-circular shaped with a “V” shaped portion protruding into said hole, said portion having a first angle. 
     
     
         7 . The anti-kickback saw chain of  claim 6 , further including a rivet having a generally semi-circular shape with a “V” shaped section missing from said circle, wherein said section comprises a second angle. 
     
     
         8 . The anti-kickback saw chain of  claim 7 , wherein said rivet is configured to mate with said rivet hole and secure said safety link to said holding link. 
     
     
         9 . The anti-kickback saw chain of  claim 8 , wherein said first angle is less than said second angle. 
     
     
         10 . The anti-kickback saw chain of  claim 1 , wherein said tooth is removably mounted to said holding link without a fastener. 
     
     
         11 . The anti-kickback saw chain of  claim 1 , further including a safety lobe, extending higher than a depth gauge on said holding link. 
     
     
         12 . A saw chain including a plurality of links, said saw chain comprising:
 a plurality of holding links each having an upstream end and a downstream end relative to a direction of travel of the chain and a first side and a second side;   a plurality of replaceable teeth that include a cutting surface, said teeth being adapted to be removably retained on the downstream end of said holding link; and   a plurality of safety drive links comprising a straight back edge, wherein said straight back edge is adapted to limit rollback movement of said tooth and prevent kickback of the saw chain.   
     
     
         13 . The saw chain according to  claim 12 , wherein said plurality of holding links each include a tab extending outwardly from the first side of the downstream end of said holding link. 
     
     
         14 . The saw chain according to  claim 13 , wherein said tabs are positioned on said holding links to contact the straight back edge of said safety drive links pivotally connected to said holding links on said first side and limit rollback movement of the holding links. 
     
     
         15 . A method of preventing kickback in a saw chain with replaceable cutting teeth, including a plurality of links each having an upstream end and a downstream end in a direction of travel of the chain, comprising the steps of:
 removably mounting a removable tooth to a holding link having a first side and a second side;   pivotally connecting the upstream end of a safety drive link to the first side of the downstream end of said holding link, said safety drive link comprising a straight top edge; and   obstructing rollback movement of said holding link with said straight top edge of said safety drive link to maintain a generally flat cutting plane.   
     
     
         16 . The method of  claim 15 , wherein said rollback movement is further obstructed by a tab located on the first side of said holding link. 
     
     
         17 . The method of  claim 15 , wherein said safety drive link is pivotally connected to said holding link by mating a rivet hole with a complementary rivet, said rivet hole being generally semi-circularly shaped with a “V” shaped protrusion extending therein, said protrusion having a first angle and said rivet being generally semi-circularly shaped with a “V” shaped section missing from said circle, said section having a second angle, wherein said first angle is less than said second angle. 
     
     
         18 . The method of  claim 17 , wherein mating said rivet hole with said rivet further obstructs rollback movement by said holding link. 
     
     
         19 . A powdered metal rivet comprising:
 a first end having a head portion;   a second end, opposite said first head, comprising a generally cylindrical tail with a uniform diameter; and   a doughnut shaped bearing surface positioned between said first end and said second end, said bearing surface comprising powdered metal.   
     
     
         20 . A method for preventing kickback in a saw chain comprising a plurality of links, each having an upstream end and a downstream end according to a direction of travel of the chain, said method comprising the steps of:
 removably mounting a removable tooth to a holding link;   providing a safety drive link with a generally semi-circularly shaped rivet hole, said rivet hole including a “V” shaped protrusion extending therein, said protrusion having a first angle;   molding a powdered metal rivet having a diameter less than said rivet hole, said rivet having a semi-circular shape with a “V” shaped section missing therefrom, said section having a second angle, larger than said first angle; and   pivotally connecting the upstream end of the safety drive link to said holding link, wherein said triangular portion limits the rotational movement of said holding link.