US 4,311,074 AGranted

Band saw blade tightening device

AssigneeWells Manufacturing Corporation

InventorTimothy C. Titus

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Abstract

A blade tensioning mechanism for a band saw is provided with a block slidably mounted on the saw frame and carrying a movable, non-driven, i.e., idler, band saw blade wheel. A link extends through a cam follower secured to the block and carries a pivotally mounted cam for engaging the cam follower. The end of the link opposite the cam is threaded and is engaged in a threaded bore of a rotatable shaft which is carried on the frame and which is restrained against displacement relative to the frame. A handle is connected to the shaft through a preset torque limiting device whereby the blade can be pretensioned to a predetermined amount by turning the handle to move the link, cam follower, block, and idler wheel relative to the frame. The cam can be subsequently pivoted against the cam follower to further move the idler wheel a predetermined amount to apply a final, operational tension.

Claims10

Dependent claims

In a band saw having a frame, spaced-apart band wheels rotatably mounted to said frame in a common plane of rotation and adapted to receive and carry an endless band saw blade thereon, a blade drive means operably associated with one of said band wheels to drive that band wheel, and another of said band wheels being an idler wheel and additionally being mounted for movement in said plane of rotation relative to said driven band wheel to tension said endless band saw blade, an improved blade tensioning mechanism which comprises:

a block slidably mounted to said frame and carrying said idler band wheel rotatably mounted thereon;
an apertured cam follower integral with said block;
a threaded, elongated link having a distal end extending through said apertured cam follower;
detent means mounted on said link for engaging said block;
link receiving means carried by said frame and threadingly engaged with said link, said link receiving means being braced against displacement relative to said frame, but rotatably mounted relative to said frame and link;
a handle for rotating said link receiving means thereby effecting displacement of said threadingly engaged link and of said detent means relative to said frame along the lingitudinal axis of the link to move said block and pretension said band saw blade;
torque limiting means operably disposed between said handle and said link receiving means for accommodating rotation of said link receiving means by said handle only until a predetermined torque value is attained;
and
cam means mounted on said link distal end for engaging said cam follower to displace said block a predetermined distance along the longitudinal axis of said link thereby tensioning said band saw blade to operational tension.

6 more elements

In a band saw having a frame, a pair of spaced-apart band wheels rotatably mounted to said frame in a common plane of rotation and adapted to receive and carry an endless band saw blade thereon, blade drive means operably associated with one of said pair of band wheels, and the other of said pair of band wheels additionally being mounted for movement in said plane of rotation relative to said one band wheel to tension said endless band saw blade, an improved blade tensioning mechanism which comprises:

a block slidably mounted to said frame and carrying said other band wheel rotatably mounted thereon, said block including an engagement surface;
a threaded, elongated, cylindrical link having a distal end extending along said block;
detent means mounted on said link for engaging said engagement surface;
link receiving means carried by said frame and threadingly engaged with said link, said link receiving means restrained against displacement relative to said frame but permitted to rotate relative to said frame and link;
a handle for rotating said link receiving means thereby effecting displacement of said threadingly engaged link and of said detent means relative to said frame along the longitudianal axis of said link to move said block and pretension said band saw blade;
torque limiting means operably disposed between said handle and said link receiving means for accommodating rotation of said link receiving means by said handle only until a predetermined torque value is attained;
and
additional means carried on said link for engaging said engagement surface and for being operated to increase the spacing between said band wheels a predetermined amount thereby further tensioning said band saw blade to operational tension.

5 more elements

Dependencies are inferred from the claim text.