IMPROVEMENTS IN MORTISING MACHINES FOR MAKING MORTISES IN ALL KINDS OF WOOD AND JOINERY
Year: 1869

page_text: LETTERS PATENT to Martin Benson, of No. 9, Southampton Buildings,
Chancery Lane, in the County of Middlesex, for the Invention of
IMPROVEMENTS IN MORTISING MACHINES FOR MAKING MORTISES IN ALL KINDS
OF WOOD AND JOINERY."-A communication from abroad by John
Richards, of Philadelphia, Pensylvania, United States of North
America.
Sealed the 30th November 1869, and dated the 15th June 1869.
PROVISIONAL SPECIFICATION left by the said Martin Benson at
the Office of the Commissioners of Patents, with his Petition, on
the 15th June 1869.
I, MARTIN BENSON, of No. 9, Southampton Buildings, Chancery
Lane, in the County of Middlesex, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN MORTISING MACHINES FOR MAKING
MORTISES IN ALL KINDS OF WOOD AND JOINERY," a communication to me from
abroad by John Richards, of Philadelphia, Pensylvania, United States
of North America, to be as follows:-
The Invention of these improvements relates to machines for mortising
wood, and are adapted under the several modifications herein-after

page_text: specified to forming mortises of any size in all kinds of wood and
joinery, and relates, first, to a mortising machine adapted to forming
mortises in the heaviest class of work when the strength or weight of
the attendant is not sufficient to operate the feed movement of the
chisel bar, and when the material is too heavy to be feed to the chisel
to receive its action; and consists in connecting the feeding mechanism
of the chisel bar with the driving power by means of a frictional clutch
controlled by a treadle, and so arranged that the chisel may be gradually
brought down into the material, and with positive motion, but at the will
and control of the operator. There is connected with the crank wheel a
continuously reciprocating ram or carrier moving in guides on the front
of the machine, to this is attached the chisel bar by a strong right and
left threaded screw, this screw revolves by means of a pair of bevel gear
wheels, one of which is upon the shaft carrying the friction clutch
mentioned, which consists of two disc plates with an elastic washer
between, one plate is connected with the crank shaft by a belt, one runs
loose upon the shaft, the other is feathered to the shaft and connected
with the treadle which presses these plates together, giving motion to
the gears and by them revolving the screw refered to which forms the
chisel bar out of the ram and feeds the chisel down into the work. To
graduate and control this motion a weight is employed which is raised
by a strap winding around the shaft that is driven by the friction clutch,
and as the diameter is constantly increased as the folds of this strap
accumulate the resistance is increased as the weight raises, thereby
enabling the opeator to move the chisel bar up or down or keep it at
one position with reference to the ram at pleasure. This weight in un-
winding reverses the friction clutch and returns the chisel bar to its
highest position.
This Invention also relates to a mortising machine having a graduated
stroke of the chisel bar, and is adapted to work of a smaller size and
when mortises need to be more rapidly made, but in material that is too
heavy or too large to be fed to the chisel, and consists in connecting the
chisel bar to the crank wheel by means of two links pivoted together
in the centre, and this joint connected to a third link to a radial arm
operated by a treadle in such manner that the chisel may be stopped
when the crank wheel is in motion, and when so stopped will stand at
or above the upper extreme of its stroke, the whole being so arranged
that the chisel bar may be gradually thrown into mortion, progressing

page_text: downward at the same time in such manner as to form mortices nearly
as deep as the whole motion of the chisel; to prevent vibration of the
connecting links and to steady their action there is a break wheel
placed upon the axis of the radial arm that operates therin. This wheel
is fitted with a rubber set up by a screw sufficiently tight to prevent
tremulous motion, but loose enough to allow of its being turned with
the treadle.
It further relates to a machine adapted to a smaller class of work in
which the chisel bar has a constant reciprocating motion moving at all
times with a uniform range and not fed to the material so previously
described, the table with the material upon it being fed up to the chisel
by a treadle. The chisel is reversed automatically at each stroke of the
table, the chisel bar making a half rotation each time by means of a belt
connecting it with the crank shaft and an escapement or let off motion
that receives it at the proper time; the belt mentioned is sufficiently
tight to rotate the bar in reversing, but in the interval slips on the
surface of the pullies; the escapement consists of a sleeve surrounding
and feathered to the chisel bar on which there is a hook working within
a yoke, the yoke moving alternately in two directions allows the sleeve
to make a half revolution at each motion, the hook catching into
opposite stops each time.
This Invention also relates to an adjustment of the treadle of such
machines by means of a pawl an rack in such manner that the move..
ment of the treadle shall correspond to the depth of the mortise and
avoid unnecessary labour in operating the machine, the treadle is pivoted
at its fulcrum and provided on its under side with a paul that falls into
a rack as the treadle is raised, so that the operator has only to left the
treadle to the proper height, where it is retained by the paul or is lowered
by simply releasing the paul and allowing it to drop to the desired
position, where it remains during the mortising
It further refers to improvements in the carriages or tables of morticing
machines and the manner of adjusting them, and consist in mounting
the carriage upon a cylindrical stud, on which it can be adjusted laterally
or pivoted so as to stand at any angle for diagonal mortice, and in
combination with such tables proper stops to keep the material down
if fed by hand, or the stops dispensed with and the cramp screw and
carriage used.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Martin Benson in the Great Seal Patent Office on
the 8th December 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, MARTIN
BENSON, of No. 9, Southampton Buildings, Chancery Lane, in the
County of Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fifteenth day of June, in the year of
our Lord One thousand eight hundred and sixty-nine, in the thirty-second
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said Martin. Benson, Her special licence that I, the
said Martin Benson, my executors, administrators, and assigns, or such
others as I, the said Martin Benson, my executors, administrators, and
assigns, should at any time agree with, and no others, from time to
time and at all times thereafter during the term therein expressed, should
and lawfully might make, use, exercise, and vend, within the United
Kingdom of Great Britain and Ireland, the Channel Islands, and Isle of
Man, an Invention for "IMPROVEMENTS IN MORTISING MACHINES FOR MAKING
MORTISES IN ALL KINDS OF WOOD AND JOINERY," a communication to me from
abroad by John Richards, of Philadelphia, Pennsylvania, United States
of North America, upon the condition (amongst others) that I, the said
Martin Benson, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and seals, should par-
ticularly describe and ascertain the nature of the said Invention, and
in what manner the same was to be performed, and cause the same
to be filed in the Great Seal Patent Office within six calendar months
next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Martin Benson, do hereby declare
the nature of the said 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 machines for mortising wood, and is adapted
under the several modifications herein-after specified for forming mortises
of any size in all kinds of wood and joinery. It relates, first, to a
mortising machine adapted to forming mortises in the heaviest class of
work when the strength or weight of the attendant is not sufficient
to operate the feed movement of the chisel bar, and when the material

page_text: is too heavy to be fed to the chisel to receive its motion. It consists
in connecting the feeding mechanism of the chisel bar with the driving
power by means of a frictional clutch controlled by a treadle, and so.
arranged that the chisel may be gradually brought down into the
material, not with positive motion, but at the will and control of the
operator. There is connected with the crank wheel a continuously
reciprocating ram or carrier moving in guides on the front of the
machine; to this is attached the chisel bar by a strong right and left
threaded screw, which revolves by means of a pair of bevil gear wheels,
one of which is upon the shaft carrying the said friction clutch, which
consists of two disc plates with an elastic washer between them; one
plate is connected with the crank shaft by a belt and runs loose upon
the shaft, the other is feathered to the shaft and connected with the
treadle which presses these plates together, giving motion to the gears,
and by them revolving the screw before referred to, which forces the
chisel bar out of the ram and feeds the chisel down into the work.
To graduate and control this motion a weight is employed which is:
raised by a strap winding round the shaft which is driven by the
friction clutch, and as the diameter is constantly increased as the
folds of this strap accumulate the resistance is increased as the weight
rises, thereby enabling the operator to move the chisel bar up or
down, or to keep it at one position at pleasure with reference to the
ram. This weight in unwinding reverses the frictional clutch and returns
the chisel bar to its highest position.
This Invention also relates to a mortising machine having a graduated
stroke of the chisel bar, and is adapted to work a smaller size, and
where mortises are required to be more rapidly made, but in material
that is too heavy or too large to be fed to the chisel, and consists in
connecting the chisel bar to the crank wheel by means of two links.
pivotted together in the centre, and this joint connected by a third
link to a radial arm operated by a treadle in such manner. that
the chisel may be stopped when the crank wheel is in motion,
and when so stopped will stand at or above the upper extreme of
its stroke, the whole being so arranged that the chisel bar nay, be
gradually thrown into motion, progressing downward at the same
time in such manner as to form mortises nearly as deep as the whole
motion of the chisel. To prevent vibration of the connecting links
and to steady their action a break wheel is placed upon the

page_text: axis of the radial arm that operates them. This wheel is fitted
with a rubber set up by a screw sufficiently tight to prevent
tremulous motion but loose enough to allow of its being turned with
the treadle.
It further relates to a machine adapted to a smaller class of work
in which the chisel bar has a constant reciprocating motion, moving
at all times with a uniform range and not fed to the material as
previously described, the table with the material upon it being fed
up to the chisel by a treadle. The chisel is removed automatically
at each stroke of the latter, the chisel bar making a half rotation.
each time by means of a belt connecting it with the crank shaft,
and an escapement or let-off motion that releases it at the proper
time, the belt is sufficiently tight to rotate the bar in reversing but
in the interval slips on the surface of the pullies. The escapement
consists of a sleeve surrounding and feathered to the chisel bar on
which there is a hook working within a yoke moving alternately in
two directions which allows the sleeve to make a half revolution at
each motion, the hook catching into opposite stops each time.
This Invention also relates to an adjustment of the treadle of such
machines by means of a pawl and rack in such manner that the
movement of the treadle shall correspond to the depth of the mortise
and avoid unnecessary labour in operating the machine. The treadle
is jointed at its fulcrum, and provided on its inner side with a pawl
which falls into a rack as the treadle is raised, so that the operator
has only to lift the treadle to the proper height, where it is retained
by the pawl or is lowered by simply releasing the pawl and allowing
it to drop to the desired position, where it remains during the
mortising.
It further refers to improvements in the carriages or tables of mor-
tising machines and the manner of adjusting them, and consists in
mounting the carriage upon a cylindrical stud on which it can be
adjusted laterally or pivotted so as to stand at any angle for diagonal
mortises, and in combination with such table proper stops to keep the
material down if fed by hand, or the stops dispensed with and the cramp
screw and carriage used.
It is well understood by those skilled in the art that machines adapted
to mortising for doors and sash or other light work cannot be used
for heavy work, the greater strength of the parts and consequently

page_text: greater weight required for heavy work such as framing for structures
and railway car work prevents a high speed of such machines, while in
the lighter work alluded to rapidity of performance is of the greatest
importance, and lighter machiues required, with such modifications of
the mechanism as will admit of rapid motion.
This Invention consists in several modifications of a mortising machine
so constructed and arranged that the several kinds of mortising can be
done in the most rapid and perfect manner.
The first modification to be described and represented on Shee; 1,
Fig. 1, of the Drawings, is intended for heavy work, the main feature
being in connecting the feeding mechanism of the chisel bar with
the driving power by means of a friction clutch, controlled by a
treadle in such manner that the chisel may be gradually fed down
to the wood at the will and control of the operator and without any
movement of the treadle except to regulate the action of the friction
clutch,
The nature of the operation of this machine and the manner of
using it will be explained by referring to Sheet 1, Fig. 1, of the Drawings
which represent a side elevation of a mortising machine embodying the
improvements referred to.
On the front of the main frame A, there is a slide or carrier having
the two bearings B, C, and I, this carrier has a reciprocating motion up
and down on the front of the machine, working in proper guides, and
is moved by a crank wheel or excentric on the end of shaft D, the
connection being by a link of the usual construction as shewn in
dotted lines; the chisel bar E is bored out at the lower end to receive
the chisel F, and is threaded internally at the top end to receive the
screw g, this screw has on one end a left hand, and on the other a right
hand thread of coarse-pitch, the lower end of screw g, as before mentioned
is threaded in the top of the chisel bar E, the other passes through a
nut fastened in the bearing B, this screw with the bearings B, C, and I,
and chisel bar E, have a continuous reciprocating motion by means of
the erank and connecting link as before explained. At h is shewn a
pair of bevel wheels mounted on and supported by means of a bearing
which is fixed to the main frame, the screw plays freely through the
bevel wheel as shewn and has a feather to keep it from turning except
by the action of the wheels, by rotating this screw g it moves through
the nut in the bearing B, and also moves in the chisel bar E, to

page_text: correspond with the pitch of the thread, the threads being reverse, right
hand on one end of the screw, and left hand on the other, it moves down
through the nut in B, one thread at each turn, and also moves one
thread out of the chisel bar E, the result being that the chisel bar is
projected down through the bearings I and C, as the aggregate pitch of
the thread at both ends of the screw, securing by this means a rapid
movement of the chisel bar without making so coarse a thread on
screw gas to cause it to yield when the chisel F strikes the wood. To
operate, the bevel wheels h and screw 9 there is a shaft shewn in dotted
lines at n, and a pulley at o, connected by the band k with shaft D,
there is also a friction clutch at S for connecting the motion of pulley o
to the shaft n and bevel gear at h; this clutch is operated by the bell
crank and treadle P, as shewn in dotted lines in the Drawings; on the
shaft n there is a pulley at R around which the strap W winds, raising
the weight t; the strap W in winding on the pulley R constantly
increases its diameter as the weight is raised, and the weight by this
means offers a gradually increasing resistance to the action of the friction
clutch S, and to the rotation of the shaft n the pulley o runs con-
tinuously, and to operate the chisel bar the attendant presses down the
treadle P with his foot, the treadle being connected with the bell
crank U by a rod, shewn in dotted lines, which puts the friction clutch
and shaft n in motion, and by means of the wheels at revolves the
screw g, and feeds down the chisel bar E. While the shaft n is revolving
the weight t is raised, and when the friction clutch S is released this
weight reverses the motion of the shaft and screw g, returning the chisel
bar in its highest position and disengaging the chiself from the work.
The graduated resistance offered to the rotation of shaft n by the weight t
enables the operator to stop the feed of the chisel at any point, or to feed
it down at any rate of speed to suit the depth and character of the
mortises being made, the friction clutch slipping to accommodate such
movement. The chisel is reversed by means of the handle J in the usual
manner. The table and carriage for holding the timber is of the common
form, and is adjusted to various heights to accommodate the stuff
and depth of mortise by means of the right and left threaded screw V
and hand wheel X. Other portions of the machine have no special
novelty, and do not need description to be understood.
The second modification of mortising machines contained in this
Invention is one adanted to a modium alace of worl.

page_text: nor of the lightest character, but as nearly adapted to general mortising
as possible, and has a graduated stroke of the chisel bar. The chisel
when not at work has no movement but is gradually set in motion by
means of a treadle progressing downward into the wood as such motion
increases but going no higher in its upward motion than the fixed point
from which the movement commences; this movement of the chisel is
different from that of an increasing motion from a variable crank or
excentric, inasmuch as mortises can be found as deep as the whole range
of movement, the chisel stopping at the extreme upstroke as before
explained. The mechanism for producing this motion of the chisel bar
is shewn in Sheet 1 of the Drawings, Fig. 2, being a front elevation of
the machine. A is the main frame, C is a slide or cross head, to which
is attached the chisel bar a; this slide C is attached to a crank wheel d
by means of the jointed links e and o; these links are connected from
the joint at 3 to the radial arm m by means of the link S; the radial
arm m is mounted on a shaft or axis that has a bearing on the main
frame and is moved by the lever n, connection t, and treadle p; B is a
weight that acts to raise the treadle p when the foot of the operator is
removed. The mode of operation will be understood by supposing the
joint at 1 moved so as to coincide with the centre at 2, the two links e,
and S then vibrate on this as a fixed pivot point, and no motion of the
cross head c nor chisel bar a takes place, the chisel standing still at the
extreme upper point of its stroke. To put the chisel in motion the
operator presses down the treadle p, moving the arm m about one-fourth
of a revolution, thus bringing the two links e and o into a line between
the crank and centre 2, when they act as an ordinary connection between
these points, giving the cross head c and chisel bar a a reciprocating
motion equal to the throw of the crank on wheel d, the link S serving
to guide the connection at joint 3; by this arrangement any degree of
motion can be given to the chisel and throughout a space of time
to suit the nature of the work, the stroke increasing as the chisel
gradually works its way down into the wood. To regulate the move-
ment of the arm m and prevent vibration a friction clutch or disc
is put on the shaft that carries the arm m, which is adjusted to
secure a steady movement, but not so as to interfere in any great degree
with the action of the treadle p or the weight B. The carriage and
timber supporting parts at g are of the common form of construction,
except as to strength and weight, compared with the one shewn in
Fix 1

page_text: A third modification of this improvement in mortising machines is
illustrated on Sheet 2 of the Drawings, Fig. 1 being a side elevation,
and Fig. 2 a front elevation; Fig. 3 is a plan of Fig. 1; and Fig. 4, a
detail, shewing the action of the mechanism for reversing the chisel
automatically at each motion of the treadle. This machine is intended
for a lighter class of work, when the pieces to be mortised are not too
long or heavy to be raised with the carriage to receive the action of the
chisel, and is intended to operate at a much higher rate of speed than
the two modifications herein-before described, being particularly adapted
to door and sash manufacture, but yet strong enough to meet the
requirements of general joinery. In this modification the chisel bar has
a continuously reciprocating motion moving at all times with a uniform
range, and not fed down to the wood as in the former cases, but the
material to be mortised is fed up with the carriage by means of a treadle.
In a machine so constructed the mechanism is much simplified, the
chisel bar being connected directly to the crank by means of a simple
link. The reciprocating parts are also very light and simple, and can
be operated at a high speed without jar or vibration. The chisel bar
turns one-half round at each motion of the treadle, so as to square both
ends of the mortise without effort or attention on the part of the
operator, leaving him free to use both hands continuously in moving and
handling the pieces being mortised. The treadle is so arranged as to
give different degrees of movement to the table or carriage to correspond
with the depth of the mortise, so that no unnecessary movement of the
foot will take place, but be directly to the depth to which the chisel
cuts. The table or carriage is mounted on a cylindrical stud, on which
it is so pivotted as to allow mortises at any angle to be made, and is
also adjusted laterally on this stud, giving a cheap and full adjustment
of the carriage for work of all kinds.
The manner of operating will be understood by reference to Sheet 2 of
the Drawings, the letters of reference on the different Figures indicating
corresponding parts.
A is the main frame; a is the chisel bar, B is a cross head or carrier,
having a bearing for the chisel bar, and connected to the crank wheel c
by means of a link d; this carrier B moves up and down in guides
provided in the framing, and drives the chisel bar a in the fixed
bearings e and f. The upper end of the chisel bar plays freely through
the grooved pulley S, having a feather to keep it from turning except by

page_text: rotation of the pulley. The reversing pulley S is driven by the band g,
and has an intermittent motion performing a half rotation at each
motion of the treadle, the belt g slipping on the pullies when the pulley
is stopped, the belt g passes over the two idle pullies M, M, and around
the pulley on the crank shaft 4, as shewn in the Drawings. The motion
of this pulley S and the semi-rotation of the chisel bar is accomplished
by means of the mechanism shewn in enlarged detail at Fig. 4, and in
side elevation Fig. 1 of the Drawings. The whcel S has on its hub a
pawl extension, seen in Fig. 4, at i working in an eye formed on the end
of the bar ; this eye has two stop points, as shewn in Fig. 4, so that
when it is moved backward and forward the pawl i is released on one
side and stopped on the other, making a half revolution at each motion.
To work this bar ka rod m passes down to the carriage to which it is
connected at n. On the top of this rod there is a pawl o working in the
notches shewn in bar k, Fig. 1; this pawl, it will be observed, is directly
over the point when the bar k is in the centre of its movement, but
when thrown either forward or back the pawl falls to the right or left of
the point r, and striking against the shoulders t, t, moves the bar k
alternately back and forward, allowing an escapement and half rotation
of the pulley S and chisel bar a at each motion of the treadle and
carriage. The carriage for holding the timber is of the common form so
far as the means of clamping and moving the material; it is mounted on
a cylindrical stud p projecting from the sliding plate J. The carriage u
is clamped on the stud by the split sleeves and clamp screw, as shewn,
the table pivots to any angle on the stud p, and is moved laterally on
this stud for adjustment by means of the screw W. The plate g moves
freely up and down upon the face of the main frame, and is moved by
the treadle X. The height of the table is regulated by the wheel and
screw at y, which moves it up and down to suit the thickness of the
wood and depth of the material required. The treadle X is pointed at-
the fulcrum Z, and has a segment and pawl, by which it can be set at
various distances from the floor to suit the range of the carriage required,
and so that the operator need not raise his foot any higher to operate the
table than the depth of mortise requires.
Having thus described the several improvements in mortising
machines constituting this Invention, I would claim,-
Firstly. The feed movement of the chisel bar by mechanism, as shewn
in Sheet 1. Fig. 1 of the Drawings. consisting of the right and left

page_text: threaded screw g, the friction clutch S, and weight t, with the shaft n, or
other mechanism, the same as herein-before described.
Secondly. The mechanism shewn in Sheet 1, Fig. 2 of the Drawings, to
produce a graduated motion of the chisel bar of a mortising machine, in
the manner and for the purposes specified..
Thirdly. The several devices for reversing the chisel of a mortising
machine, as shewn on Sheet 2 of the accompanying Drawings.
I claim also the jointed treadle shewn in the same machine with the
devices arranged to regulate its movement in the manner specified.
I claim also the arrangement shewn for mounting the carriage of a
mortising machine on a cylindrical stud, so that it can pivot and swing
to any angle, or be adjusted laterally on the stud, in the manner and for
the purposes shewn on Sheet 2 of the Drawings, and described in this
Specification.
In witness whereof, I, the said Martin Benson, have hereunto set
my hand and seal, this Eigth day of December, in the year of
our Lord One thousand eight hundred and sixty-nine.