An Improved Mitre Cutting Machine.
Year: 1890

page_text: Date of Application, 18th Oct., 1890
Complete Specification Left, 20th July, 1891-Accepted, 5th Sept., 1891
PROVISIONAL SPECIFICATION.
An Improved Mitre Cutting Machine.
I, WILLIAM WILSON HORN, of the firm of Horn & Son, of 151 Strand,
London, Middlesex, Patent Agent, do hereby declare the nature of this inven-
tion, (a communication to me from abroad, by William R. Fox, of Grand
Rapids, County of Kent, State of Michigan, United States of America, Engineer
and Machinist) to be as follows:-
This invention relates to an improved mitre cutting machine and its object is
to obtain a machine which shall be capable of cutting any mitre, angle or bevel
required, and at the same time be made substantial and at a low cost.
În carrying my invention into effect I construct the machine as follows:
It consists of a bed-plate which is preferably of metal, and having at one side
a vertical framing either formed in one or fixed to the said bed-plate, having
guides formed in or upon the said vertical frame. Within these guides moves
a carriage having knives or cutters adjustably secured thereto. These knives or
cutters are formed with a bevelled cutting edge, a portion of the lower side of
these knives or cutters being of the full thickness of the blade to give increased
rigidity to the blade and prevent it drawing into the bed, said thickened portion
lying below the surface of the bed. Motion is imparted to the carriage by means
of a rack upon the outer side of the said carriage, and a toothed segment pivoted
upon the side of the base or bed plate and capable of partial rotation by a lever
or other suitable device.
A movable gauge which may be clamped or fixed to any desired angle with.
the knife or cutter is pivoted at one end by a link in such a manner that the
edge of the gauge nearest to the cutting blade forms a shearing edge to support
the material to be cut and prevents the cut edge breaking, and when the gauge
is thrown back or removed a post against which the gauge is supported acts
in a like manner to insure a clean cut.
A scale is engraved upon the bed to facilitate accurate adjustment of the said
gauge.
Dated this 18th day of October 1800.
HORN & SON,
Applicant's Agents.
COMPLETE SPECIFICATION.
An Improved Mitre Cutting Machine.
I WILLIAM WILSON HORN of the firm of Horn and Son 151 Strand in
the County of Middlesex Patent Agent do hereby declare the nature of this
invention (a communication to me from William R. Fox of Grand Rapids County
of Kent State of Michigan United States of America Engineer and Machinist)
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 an improved mitre cutting machine and its object is to
obtain a machine which shall be capable of cutting any mitre angle or bevel
required and at the same time be made substantial and at low cost.
In carrying my invention into effect I construct the machine preferably as
illustrated in the accompanying drawings in which
Fig. 1 shows an elevation of the back of the machine.

page_text: Fig. 3 a plan or top view with the parts removed.
Fig. 4 is a perspective view of the knife blade, and
Fig. 5 is a broken plan view of a modification."
My improved machine consists of a suitable bed plate which may be made of any
suitable metal and having at one side a vertical framing either formed in one or
fixed to the said bed plate having guides formed in or upon the said vertical frame
within which is mounted the carriage upon which the knife is moved.
Motion is imparted to the said carriage by means of a rack and segment as shewn
in Fig. 1, the rack G being fixed upon the carriage and the segment F pivotted
upon a stud u upon the bed and adapted to engage with the rack on the carriage
and to move the carriage in either direction the required distance. The segment
is moved in either direction by means of the handle U. In order to limit the
motion of the lever handle U I provide stops A, A'. They consist of lugs which
may be cast upon the frame and extend laterally to the rear in the same vertical
plane in which the handle or lever U oscillates, in imparting movement to the knife.
They are located in respect to vertical arrangement at a point where they are
adapted to arrest the motion of the lever U when the knife has reached the outer
limit of its movement.
I provide an oil chamber in the carriage as shewn more clearly in Fig. 2. The
carriage moves in grooves, one in the bed piece and the other in the upper part of
the frame of the machine. The carriage is recessed at top and bottom the recess
in the upper part being marked wand that in the lower part w' and these are
connected by a vertical passage B. The chamber is preferably filled with wicking
or some porous material to retain the oil which as the carriage moves lubricates
the ways.
Another part of the invention relates to the construction of the knife which is
shewn at c. This is fixed to the carriage by bolts N passing through slots. As
shown in the drawings there is a knife on each end of the carriage and the machine
is double acting. The knife is bevelled on the rear side as shewn in shaded lines
in Fig. 1, but the bevel does not extend fully to the lower end of the knife which
at the lower end is left at its full thickness, the bevel surface terminating at its
lower end in a curve, which is below the upper face of the bed, so that the cutting-
edge extends below said upper surface, but leaves the full thickness of the knife to
move in the groove or way on the bed. This full thickness is shown at c¹ and that
part of the groove in which it moves is shewn at y in Figs. 1 and 2.
The construction described serves a twofold purpose: first the full thickness of
the lower part of the knife forces the chips out of the way and keeps the way clear
for the carriage second it strengthens the knife and lessens the tendency to be
drawn into the bed, whereby the bed would be cut, and both the knife and the bed
injured.
An important part of my invention relates to the gage and to the means by
which the gaging-corner is maintained in the same relative position in respect
to the knife, whatever may be the angle at which the gage is set. This relative
position may be maintained by two bearing surfaces against which the free end
of the gage is supported at any required angle: and, in the present case, while
I utilize the post as one of the bearings for the gage, I provide the other bearing
in rear of the gage, instead of at the gaging end and in line therewith. The gage
corner e is shown more clearly in Fig. 3. The position of the gage D is shewn
in full lines, and the other radial lines from point e' illustrate the different
positions of the gage. The outer end of the gage is adjustably held by means
of the slot m and bolt and set screw in the manner well known. The other end
of the gage next to the knife is loosely held by means of a directing connection
consisting of a link R. This may be located near the bottom of the gage by a
countersink therein, or it may be located at the point shewn in Fig. 2 a little way
raised from the lower end of the gage being let in from the side.

page_text: The shear-edge e is at one corner of the gage end, and the opposite corner or
side of the gage bears laterally against the post C, to which it is connected by the
link R, which is pivoted to the gage at T and to the post at S. The gage turns
on the pivot T as it is swung to change the angle while lateral movement of the
gage is permitted by means of the link-connection to the pivot S, thus keeping the
It will be
corner e always in line with the cut, this line being indicated at xx.
seen that a peculiar movement of the gage-corner is necessary to effect the desired
purpose, namely to allow it to turn freely, and at the same time automatically
maintain its position along the line of the cut, that is I must provide for the turning
of the edge e in the arc of a circle, and at the same time counteract the curve
described thereby by causing the edge to move toward the post, thereby keeping it
on the line of the cut. This is done by making the edge describe a circle the
centre of which is the pivot T, and at the same time limiting the outward tendency
of the edge by the link connection to the frame. If the pivot T were a fixed pivot
when the inner end of the gage is swung to the left the shearing edge e would be
swung over the line and into the path of the knife but the lateral movement
caused by the other corner swinging in the same path on the pivot T bearing
against the edge of the post pushes the pivot T out from the post causing it to
swing on the pivot S as a centre, thus keeping it on the same straight line or in the
same plane.
A modification of this arrangement is shown on Fig. 5 in which, instead of the
pivoted link forming the directing connexion for maintaining the shearing edge in
the same relative position to the line of the cut I provide the gage with an
extension a' in its rear face which serves by reason of its curved face bearing on
the post 6 or a pin thereon to allow the shearing edge lateral movement on the line
of the cut. The pivot S may be made removable and the gage swinging out on its
front pivot used for trimming curved or irregular pieces of wood.
The forms of directing connections shewn are convenient ones, but, as any
mechanic will understand, may be varied without departing from the spirit of the
invention.
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. In combination with the bed of a mitre-cutting machine and a carriage a knife
carried thereby, said knife having a bevelled cutting edge and a lower unbevelled
portion of the full thickness of the blade, this portion of the knife being below the
upper face of the bed thus strengthening the knife on its lower bearing edge and
preventing the tendency of the knife to draw into the bed substantially as
described.
2. In a mitre-cutting machine a carriage moving in upper and lower ways, and a
knife carried thereby having a bevelled cutting-edge, and a lower portion of full
thickness moving in the lower guide-way, substantially as and for the purpose set
forth.
3. In a mitre-cutter or trimmer, a gage having a shearing edge as e, a post
forming a bearing for said edge and a connection between the rear of the gage and
the frame automatically adjustable in the movement of the gage so as to cause the
shearing-edge to move toward or from the post along the line of the cut, sub-
stantially as described.
4. In combination with a gage D having a shearing edge e the post C and a
link R in the rear of the gage and pivotted thereto at one end, its pivot forming
the centre of a circle described by the edge e and at the other end pivotted to the
frame, said pivot forming the centre of a circle described by the pivot of the link,
substantially as described.
5. The described mitre-cutter, consisting of a bed provided with ways, a carriage
moving therein carrying cutters, a segment pivotted to the bed and provided with a

page_text: handle, a rack on the carriage engaging said segment a gage at each end of the bed
having a shearing edge, posts forming bearings for said gages, and a connection
between the rear of each gage and the frame automatically adjustable in the
movement of the gage, substantially as described.
Dated this 18th day of July 1801
HORN & SON,
Agents for the Applicant.