TRADUCTION NON-DISPONIBLE

BUTTON GRINDING

Abrégé anglais

ABSTRACT OF DISCLOSURE
Buttons, e.g. on button bits, are ground by means of a concavely
peripherally profiled grinding wheel. The wheel is rotated by
matched motors to either side of it and the assembly of wheel
and rotation motors is carried by a clevis. The shank of the
clevis is chucked to a machine such as a rotary drilling machine.

Revendications

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A button sharpening tool comprising a grinding wheel
peripherally profiled to an annular concavity, at least one motor
coupled to the wheel for driving the wheel, and means for rotating
the wheel and motor assembly about an axis which is at right
angles to the grinding wheel axis of rotation.
2. The tool claimed in claim 1 including two motors of
the same kind and rating with the grinding wheel between them.
3. The tool claimed in claim 1 in which the grinding
wheel is mounted between the forks of a clevis and the shank
of the clevis is adapted to the chuck of a rotary driving
mechanism.
4. The tool claimed in claim 3 including a liquid swivel
around the shank and a passage to between the forks of the clevis
to deliver coolant liquid to the wheel.

Description

Background of the Invention
This invention relates to the grinding of buttons such ais are
found, for example, on button bits and the like.
If the buttons on a bit wear, one could replace the bit and send
the original to a repair shop some ~istance away. On the other
hand one could resurface the buttons on site. For the latter
purpose it has been proposed to utilize cup~shaped grinding tools
which are complemental to the sihape of the buttons after re-
sharpening. These have not been highly successful as the cups
normally only had a single layer of diamonds.
It would of advantage to use a more or less standard grinding
wheel for button sharpening.
Summary_of the Invention
According -to the invention a button sharpening tool comprises a
grinding wheel peripherally profiled to an annular concavity, at
least one motor coupled to the wheel for driving the wheel, and
meanis for rotating the wheel and motor assembly about an axis
which is at right angles to the grinding wheel axis of rotation.
In the preferred form of the invention there are two motors of
the same kind and rating with a grinding wheel between them so
as to achieve balance around the axis at right angles. Balance,
could, of course, also be achieved by means of a suitable
counterweight.
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Description of -the Dra~ing
The drawing shows a section through a button sharpening dev;ce
according to the invention.
Description of a Preferred Embod;ment
A concavely peripherally prof;led grinding wheel 9 is mounted
on a shaft which projects to either side of the wheel 9. The
shaft 10 is fast with the rotors of two air motors 11 mountecl
to either side of the wheel 9.
~l~vis
~ rhe motors are carried by a 6~e*i6e body 12 which forms a
narrow neck 13 ending in a shank 14. The neck 13 enters a ring
15 and is sealed by means of suitable 0-rings. The ring 15
has two inlets 16 and 17 for carrying air and coolant
respectively. The inlet 16 leads to a passage 18 which forks
and leads to the air inlets of the motors 11. The inlet 17
leads to a suitably placed outlet 19 next to the wheel 9.
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In use the shank 14 is chucked to a suitable machine for causing
it to rotate, e.g. a rotary drill chuck. Air and coolant are
connected and, with the assembly rotating, the wheel 9 is
placed against a button which is redressed on all faces
s;multaneously,
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If necessary ~he coolant could be replaced by an electrolyte
and the body or the wheel connected to one side of a DC current
supply and the bit to be sharpened to the other side to render
the b;t an anode. ~.
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