The invention relates to bandmills and in particular to an improved strain system for applying strain to a bandsaw received on the bandwheels of the mill.
The tendency towards reduced thickness of bandsaw blades, to give a thinner cut and minimize sawdust loss, has given rise to problems involving blade instability. As a result, various improvements have taken place in the development of bandmill strain systems. For example, U.S. Pat. No. 3,905,266 to Weavell discloses a bandmill strain system incorporating an air spring. Such a strain system responds sufficiently rapidly to shock loadings on the saw blade to overcome the instability referred to above. Further examples of strain mechanism using air springs are U.S. Pat. No. 3,810,409 to Allen and U.S. Pat. No. 3,838,620 to Baldrey.
Some disadvantages of strain systems utilizing air springs include the necessity of providing a relatively constant pressure source of air or other gases and a piping arrangement to conduct the gases to the air spring. Further, many air springs include relatively thin rubber components and any damage in these could result in failure of the strain system.