US 12,214,519 B2
Saw apparatus with hydraulic tensioning
Michael Boys, Tokoroa (NZ); and James Roworth, Tokoroa (NZ)
Assigned to DEERE &COMPANY, Moline, IL (US)
Filed by Deere & Company, Moline, IL (US)
Filed on Jun. 20, 2022, as Appl. No. 17/844,473.
Prior Publication US 2022/0402160 A1, Dec. 22, 2022
Int. Cl. B27B 17/14 (2006.01); A01G 23/091 (2006.01); B27B 17/02 (2006.01); F16H 7/08 (2006.01)
CPC B27B 17/14 (2013.01) [A01G 23/091 (2013.01); B27B 17/02 (2013.01); F16H 7/08 (2013.01); F16H 2007/0812 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A saw apparatus comprising:
a guide bar;
a chain driver;
an endless cutting chain trained about the guide bar and the chain driver; and
a hydraulic chain tensioning apparatus, comprising:
a hydraulic actuator configured to be driven by a hydraulic power source to act against the guide bar to maintain tension in the cutting chain; and
a tension release valve between the hydraulic power source and the hydraulic actuator, wherein the tension release valve comprises:
a check valve; and
a manual override press-button configured to maintain the check valve in an open condition while depressed, wherein the tension release valve comprises a spring detent configured to maintain the manual override press-button in a depressed condition until selectively released.