Drill mount
AssigneeRobert Bosch GmbH
InventorsKarl Wanner, Reinhardt Hahner, Wolfgang Schmid, Manfred Bleicher, Horst Sigg, Jorg Falchle
Life of this patent
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Abstract
A rotary spindle of a drill mount has a free end provided with a thread whose angle of rise is so selected that its tangent is at least equal to the coefficient of static friction of steel on steel.
Claims25
In a drill mount for connecting a drill bit to a drive unit, a combination comprising a rotary steel spindle member having a free end portion;
- an auxiliary steel member having a portion provided with a first thread;
- a second thread formed on said free end portion which is threadedly connected with said first thread, said second thread having an angle of rise the tangent of which is at least equal to the coefficient of static friction of steel on steel, whereby said members can be disengaged without requiring significant force;
- and braking means co-acting with said spindle and auxiliary members for providing a frictional braking action between said members which suffices to prevent their loosening during operation.
In a drill mount for connecting a drill bit to a drive unit, a combination comprising a rotary steel spindle member having a free end portion;
- an auxiliary steel member having a portion provided with a first thread;
- a second thread formed on said free end portion which is threadedly connected with said first thread, said second thread having an angle of rise the tangent of which is at least equal to the coefficient of static fraction of steel on steel, whereby said members can be disengaged without requiring significant force;
- and a braking ring of elastic material provided on said spindle member and co-acting with said auxiliary member for providing a frictional braking action between said members which suffices to prevent the loosening of said members during operation without requiring significant force to disengage said members.
In a drill mount for connecting a drill bit to a drive unit, a combination comprising a rotary steel spindle member having a free end portion;
- an auxiliary steel member having a portion provided with a first thread and a cylindrical shoulder portion;
- a second thread formed on said free end portion which is threadedly connected with said first thread, said second thread having an angle of rise the tangent of which is at least equal to the coefficient of static friction of steel on steel;
- and a braking ring of elastic material provided on said spindle member and co-acting frictionally with said cylindrical shoulder portion of said auxiliary member for providing a frictional braking action between said members which suffices to prevent the loosening of said members during operation without requiring significant force to disengage said members.
Dependencies are inferred from the claim text.