Chain saw machine

Claim 1

A CHAIN SAW MACHINE, COMPRISING (A) A GUIDE BAR HAVING ONE END ADAPTED FOR CONNECTION WITH SAW CHAIN DRIVE MEANS AND AN IDLER END, THE LONGITUDINAL EDGES OF SAID GUIDE BAR CONTAINING GROOVES EXTENDING THE LENGTH THEREOF, THE IDLER END PORTION OF SAID GUIDE BAR INCLUDING A PAIR OF LATERALLY SPACED SIDE PLATES; (B) AN IDLER SPROCKET JOURNALLED AT THE IDLER END OF SAID GUIDE BAR INTERMEDIATE SAID SIDE PLATES, SAID IDLER SPROCKET INCLUDING TEETH HAVING AT THE FREE EXTREMITIES THEREOF GENERALLY INCLINED FORWARD AND REAR SUPPORTING SURFACES; AND (C) A SAW CHAIN MOUNTED ON SAID GUIDE BAR AND SAID IDLER SPROCKET FOR LONGITUDINAL AND SEMI-CIRCULAR END TRAVEL RELATIVE TO SAID GUIDE BAR, SAID SAW CHAIN INCLUDING PIVOTALLY CONNECTED CENTER AND OUTER LINKS, SAID OUTER LINKS INCLUDING LOWER SURFACES ADAPTED TO ENGAGE THE PERIPHERAL LONGITUDINAL SURFACES OF SAID GUIDE BAR, AT LEAST SOME OF SAID OUTER LINKS COMPRISING CUTTER LINKS; (1) EACH OF SAID CENTER LINKS HAVING BELOW THE PIVOTAL CONNECTIONS THEREOF TO SAID OUTER LINKS A LOWER PORTION ADAPTED TO EXTEND INTO SAID GUIDE BAR GROOVES, SAID LOWER PORTION EXTENDING BELOW THE LOWER SURFACES OF EACH OF SAID OUTER LINKS A DISTANCE LESS THAN THE DEPTH OF SAID GROOVES WHEREBY DURING LONGITUDINAL TRAVEL OF THE CHAIN ALONG THE BAR THE CHAIN IS SUPPORTED SOLELY BY THE COOPERATION BETWEEN THE LOWER SURFACES OF THE OUTER LINKS AND THE PERIPHERAL LONGITUDINAL SURFACES OF SAID GUIDE BAR; (2) THE LOWER PORTION OF EACH OF SAID CENTER LINKS ALSO HAVING AT THE FORWARD AND REAR EDGES THEREOF SUPPORTING SURFACES ADAPTED FOR ENGAGEMENT WITH THE REAR AND FORWARD SUPPORTING SURFACES OF SAID SPROCKET TEETH, SAID CENTER LINK SUPPORTING SURFACES BEING ADJACENT BUT SPACED DOWNWARDLY FROM THE LOWER SURFACES OF SAID OUTER LINKS, THE FOOT PORTIONS OF SAID CENTER LINKS BEING OF A SIZE AND CONFIGURATION TO DEFINE SPACES IN THE BOTTOMS OF THE GROOVES BETWEEN SPROCKET TEETH WHEN THE SUPPORTING SURFACES OF THE SPROCKET TEETH ENGAGE THE SUPPORTING SURFACES ON THE CENTER LINKS, SAID SPROCKET BEING SO JOURNALLED BETWEEN SAID SIDE PLATES THAT THE LOWER PORTIONS OF THE OUTER LINKS ARE SPACED FROM THE GUIDE BAR SIDE PLATES WHEN THE SUPPORTING SURFACES ON THE SPROCKET TEETH ENGAGE THE SUPPORTING SURFACES ON THE CENTER LINKS, WHEREBY DURING SEMI-CIRCULAR END TRAVEL THE SAW CHAIN IS SUPPORTED SOLELY BY THE COOPERATION BETWEEN THE SUPPORTING SURFACES ON THE EXTREMITIES OF THE SPROCKET TEETH AND THE SUPPORTING SURFACES ON THE CENTER LINKS.