Improvements in Apparatus for use in Grinding Tools.
Year: 1897

page_text: Date of Application, 6th July, 1897-Accepted, 2nd Oct., 1897
Improvements in Apparatus for use in Grinding Tools.
I, HENRI CHARLES BEKKING, Engineer of 40 Choorstraat, Utrecht in the Kingdom
of The Netherlands do hereby declare the nature of this invention and in what manner
the same is to be performed, to be particularly described and ascertained in and by
the following statement :-
This Invention relates to a grinding machine for tools, implements, and the like
which according to its size may be used in connection with grinding stones of large
diameter as well as in conjunction with stones of small diameter and the operation of
which is carried out by means of the lever mechanism of a suitable support or bench.
When hard tools, such as gravers, cutters, chisels, turning tools of all description
are ground by hand with the addition of water on grinding stones which are slowly
rotated in order to prevent the softening of the cutting edges, the stone becomes soon
unfit to produce a horizontal grinding and must be dressed again for further use.
The fact of the grinding stone becoming useless is due to the irregular biting or
wearing action, when small tools are ground as well as to irregularities occurring in
the hardness of the stone when grinding wider tools such as planing irons, knifes,
carving tools, &c.
In the first case cuts or rifts are formed in the stone, these cuts being polygonal
in the second case. The frequent dressing of the stone thereby required soon wears
out the same and forms an important and costly defect which however has been
hitherto considered unavoidable in making use of hand grinding machines. This
Invention has for its object to remedy this defect in a simple and yet thorough
manner and with a positive result.
In front of the grinding stone B turning in the stand is arranged a support the
lower slide C of which can be moved parallel to the axis of the grinding stone by the
levers x as far as desired, while the upper sliding block D can be actuated at right
angles to this direction by means of the levers y. A circular motion of the upper
part of the support consisting of the two slides C and D is effected by the bearing
arrangement carried on the lower part of the support F and capable of being turned
round at E by the handle. The top plate sliding on the upper slide D and provided
with the bearing g serves to receive the fork h turning on the bolt i whose opposite
end h¹ forms a lever. The position in which this lever can be fixed within the limits
allowable is determined by the screw k. In the forked end of h is held the tool
holder & the head of which contains the tightening screw s¹ while its downward
extension contains the hard roller 7 which is free to turn on a pin.
When the tool required to be ground is fixed in the holder s by the screw 81 and
is moved forward by the levers y against the rotating grind stone B, it will appear
obvious that at the moment when a simultaneous contact with the stone is effected
by the cutting edge of the tool on the one side and by the roller r on the other hand,
the latter running in a direction contrary to the direction of motion of the grindstone,
there cannot be any indentations or cuts formed in the said stone. This roller acts
to a certain extent as a counter bearing for the tool which is being ground and
which is pressed against the stone so long as needed while the grinding continues on
account of the pressure on y. The simultaneous action of the set of levers a draws
the tool, within the lateral limits which can be accurately adjusted, over the whole

page_text: width of the grindstone and prevents irregular wear and consequently all wilful or
accidental misuse of the same.
The inclination at which the grinding is to be effected is regulated when the
grindstone is at rest partly by adjusting the lever end h' by means of the screw k
and partly by allowing the tool which has to be ground to protrude more or less out
of the holder 8. Owing to this last adjustment the tool can be safely ground and can
be provided with several grinding planes or facets having well determined proportions
between them. If instead of the cylindrical roller a roller with a curved upper
surface is used, and properly adjusted upon a suitable stone, curved and convex
grinding surfaces may be formed such as occur in grooving tools, provided E and y
are suitably manipulated.
=
In consequence of the mobility of the tool holder s in which the tool is fixed
directly and which oscillates in the forked piece, a resilient action is imparted to the
tool during the grinding process, as the sliding roller r which acts as a counter-
bearing and turns in an opposite direction to that in which the grindstone turns can
never be attacked, while the tool becomes more and more inclined relatively to the
grindstone as the grinding operation continues and hence accomplishes a motion
which is thoroughly independent of the driving action of the levers y.
independent oscillating motion of the tool holder s is the means which has to replace
the "feeling" failing in rigid mechanical appliances..
This
To explain the object of the Invention relating to the improvements above set forth
it is necessary to add the following remarks:-
The carrying out of grinding operations is regulated by "feeling" but this is
rendered entirely illusory when using mechanical contrivances even if they are
actuated by hand, so that instead of grinding a tool, the latter cuts or burrows into
the grindstone and turns the surface off the same like in a lathe.
"
•
It is in order to prevent such paring off of the stone that this Invention has been
made, by holding back the tool holder arranged to oscillate and to carry the tool
directly and by the flexible or resilient action of the tool on the grindstone, which
means efficiently replace the "teeling which fails in mechanical contrivances.
This likewise explains the further technical effect produced whereby grindstones
which are not quite round. become efficient after constant usage in connection with
the grinding mechanism and must remain so, as the tool to be ground bears resiliently
upon the highest points of the stone while on the other hand as the tool is guided
over the full width of the grindstone. indentations, cuts or grooves cannot possibly be
formed.
Having now particularly described and ascertained the nature of my said Inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:
1. Grinding mechanism for tools characterized by a forked piece movable and
adjustable and supported and driven or actuated by a suitable device, this forked
piece being provided with a tool holder which is free to move that is to say to oscillate
therein and into which the tool is directly attachable, while its lower sliding roller
forms a resilient counter-bearing and at the same time imparts a certain amount of
flexibility to the action of the tool in order to form plane or curved ground surfaces
on the tools or other article being ground and with a view to uniformly yet safely act
on the grindstone and ensure its constant use.
2. Grinding mechanism of the kind above claimed in combination with 'a
supporting contrivance actuated by a lever as described and shown.
Dated this 5th day of July 1897.
CRUIKSHANK & FAIRWEATHER,
Chartered Patent Agents,
62 St. Vincent Street, Glasgow, Agents for the Applicant.