An Improved Cutting Tool for Wood Working Machinery.
Year: 1889

page_text: An Improved Cutting Tool for Wood Working Machinery.
We RUDOLF VON SCHMITZ, Civil Engineer and GUSTAV HEYMEIER, Sculptor,
both of Bremen in the Empire of Germany 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 the improved arrangement and construction of a cutter or
cutter head or chuck whose characteristic feature is that it possesses an exchangeable
or removable blade and can be provided with a shield in such a manner that the
operative working the cutter could not under any ordinary circumstances be wounded
(i.e. cut) in using the same.
Our improved cutting tool with blade and shield is represented in the accompanying
drawings in which Figure 1 shows a vertical section of the cutter head. Figure 2
shows an external view thereof. Figure 3 is a section through the blade. Figures 4
and 5 show a modification of the cutter head for smaller blades which work concealed
in wood.
The cutter head as shown in Figures 1 to 3 is arranged as follows:-The shaft a
or, so called spindle is slotted from a to a² for the reception of the cutter. In this
slot is first arranged a block or wedge c of very hard steel which rests by means of
the projection thereon in a corresponding recess of the cutter shaft a and is pro-
vided on both sides with projections e. The block or wedge c is prevented by its pin
or projection from moving in a radial direction and serves for receiving and holding
fast the steel cutter m m².
The block is provided at its inner side at c¹ with fine grooves or flutes and
the cutters m m¹ are fluted in a similar manner for the purpose of giving better
adhesion.
The cutters m m¹ are arranged in such manner that one serves to cut when the
direction of rotation is to the right hand side and the other when it is to the left
hand side. Both cutters m m' lay upon one another and aro stiffened by a plate m¹
bent at m³ in the shape of an arm. These blades further rest in the slots a¹ a² of
the cutter shaft while they are supported and fixed in other points by a ring a bearing
thereon and slotted at d¹ the said blades being grooved or fluted at ee and thus form
a shoulder for the ring d. The blades mm² are covered over by the shield
ring which has a somewhat greater diameter than that described by the cutter in
its rotation so as to thoroughly envelope the latter.
The disc f is firmly clamped by means of a washer placed below the screw nut h.
The ring is provided at its inner sides with four projections or clasps i having for
their object to hold the blades together laterally. The disc whose lower edge is
only slightly higher than the top of the wood required to be operated upon serves as
a shield or protecting device for the operative as the disc f is slotted at fif in order
to permit the cutter to be watched when working. The blades are thus held tightly
and adjustably while being at the same time provided with a shield or protecting
device which never fails in its purpose.
To remove the cutter m the. nut is loosened whereby the disc f is released the
ring d is then lifted and the cutter blade m removed from the block c and laterally
withdrawn. The new blade is then put in and the foregoing succession of operations
reversed.
For smaller cutters namely for those which operate while entirely concealed in
the wood the shield or protecting disc f can be dispensed with the cutter being then
fixed in the manner hereinafter described with reference to Figures 4 and 5 of the
drawings. Instead of the blades being held by the disc fa second toothed block or
wedge similar to the block c may be pushed through the slots a¹ a¹ of the cutter

page_text: shaft the said block or wedge k being held by a split ring i similar to the ring d.
The ring is fixed by the nut h. The ring i serves also as a guide for the wood
which is being bored or cut. The -parts can be easily and safely fixed and released
in both modes of carrying the invention into practice.
Having now particularly. described and ascertained the nature of our inven-
tion and in what manner the same is to be performed we declare that what we
.claim is :-
1. A cutter head or chuck having exchangeable blades m m² and furnished with a
shield or protecting device in which the said blades m m² are securely held by means
of a block or wedge provided with flutes c¹ and projections e and fitted in the cutter
shaft a these blades being further maintained in a central position by means of the
slotted ring d and the disc f whereby the blades placed one upon the other are
arranged to operate on the right as well as on the left hand side and can be
supported or stiffened by means of a cap m¹¹ substantially as and for the purposes
hereinbefore described.
2. The modification of the cutter head described in the above claim whereby the
ring d and safety disc fare replaced by a second block or wedge k and ring i placed
over the same substantially as and for the purposes herein before described.
Dated this 15th day of March 1889
TONGUE & BIRKBECK,
34, Southampton Buildings, London, W.C., Agents for the Applicants.