IMPROVEMENTS IN THE ART OF MANUFACTURING SAW BLADES, AND IN APPARATUS THEREFOR."
Year: 1877

page_text: LETTERS PATENT to Sydney Pitt, of Sutton, in the County of Surrey, for the
Invention of "IMPROVEMENTS IN THE ART OF MANUFACTURING SAW BLADES,
AND IN APPARATUS THEREFOR." A communication from abroad by James
Alford House, Mechanical Engineer and Expert, of Bridgeport, in the County
of Fairfield, and State of Connecticut, United States of America.
Sealed the 8th September 1877, and dated the 12th July 1877.
" IMPROVEMENTS IN THE
COMPLETE SPECIFICATION filed by the said Sydney Pitt at the Office of
the Commissioners of Patents on the 12th July 1877.
SYDNEY PITT, of Sutton, in the County of Surrey.
ART OF MANUFACTURING SAW BLADES, AND IN APPARATUS THEREFOR."
A com-
munication from abroad by James Alford House, Mechanical Engineer and Expert,
of Bridgeport, in the County of Fairfield, and State of Connecticut, United States.
of America.
My Invention chiefly relates to the forming of teeth upon fret or scroll saw
blades. One of my objects is to both cut and set, or completely form the teeth of
a saw blade at a single operation. To this end my improvement consists in forming
the teeth upon the blade as it is fed forward by successive cuts of a chisel or cutter
reciprocated at an angle to the edge of the saw blade, operating in or substantially
in the plane of the blade, and presented to the blank with its point or edge inclined
alternately in opposite directions, whereby the teeth are pressed or forced slightly
sidewise to the right and left alternately as the cuts are made from the edge of the
blank towards its centre or back.
Another object of my Invention is to cut the teeth by a chisel operating upon a
saw blade edgewise thereof, and at an acute angle thereto. To this end my im-
provement consists in forming the teeth upon a saw blade by means of a reci-
procating chisel moving in the plane of the saw blade, and operating by successive
cuts upon the edge of the blade as it is moved in a path intersecting that of
the chisel,
My object further is to form a number of saws from a blank by automatically
cutting it up into widths to form the blades at the same time the teeth are being
cut, to which end my improvement consists in traversing the blank so as to present
ו...

page_text: the saw blade edge to the chisel for cutting the teeth as before described, and moving
the blank past and in contact with a cutter to gradually cut the blank and finally
sever the toothed blade therefrom.
The objects of my Invention also are to cut several series of teeth at intervals
upon the edge of the blank to form a number of sets of teeth in the same line
upon a single long blank suitable for cutting into lengths to make separate saw
blades; to ensure the regular feeding of the blank to the chisel or cutter; to cut
the blank into slips of the width desired to form a series of blades; to firmly sup-
port the blank and render it readily adjustable to gauge the width of strips to be
cut and the depth of the cuts of the chisel, and generally to improve the details of
the mechanism.
The subject matter claimed for accomplishing these ends will herein-after specifically
be designated.
My Invention also consists in certain novel constructions of mechanisms and com-
bination of devices which will herein-after specifically be designated.
The accompanying Drawings represent a suitable organisation of mechanism for
carrying out my Invention, all my improvements being illustrated thereby. Some
of my improvements obviously however may be used without the others, and the
Invention in part carried out by mechanism differing somewhat in details of con-
struction from that therein shown and herein described.
Plate I., Figure 1, is a plan or top view; Figure 2, a side elevation.
Plate II., Figure 3, an elevation of the side opposite that shown by Figure 2.
Figure 4 is a view partly in elevation and partly in transverse section on the line 1, 1,
of Figure 2, representing the blank holding and feeding apparatus.
Figure 5 is a view in elevation, partly in section of the chisel supporting and
operating mechanism on an enlarged scale.
Figure 6 a section on the lines 2, 2, of Figures 2 and 4, showing the devices for
adjusting the blank and regulating the width of the strips or saw blades cut
therefrom.
Plate IV., Figures 7, 8, 9, and 10, are diagrams illustrating my improved method
of forming the teeth.
Figure 11 a plan or edge view of a portion of a saw blade with the teeth formed
thereon in the manner represented by the diagrams. Figures 7 to 11, both in-
clusive, are on an enlarged scale to more clearly show the Invention.
The mechanism is supported by a suitable base or standards A, A¹, and a strong
frame or supporting beam A2, mounted at its ends upon these standards. A saw
blank carrier or holder B is moved end wise of this frame automatically to present
the edge of the blank to a chisel or cutter operating as will herein-after be ex-
plained.
The carrier or blank feeder is represented by the Drawings as composed of a body
portion or frame centrally recessed and provided with inclined flanges b, b', at its
back, which fit so as to be capable of sliding endwise of the longitudinal sup-
porting ledge B¹ (see Figure 4). A plate spring a, resting at its ends in notches in
the upper surface of the under bearing of the blank frame, and pressing against the
under surface of the lower part of the ledge of the main frame, compensates wear
and keeps the upper flange b in proper contact with the ledge; any other suitable
well-known guide-way for the carrier, obviously, may be substituted for that
described. A movable or pivoted clamping jaw or vice C, operated by a screw C³,
serves to hold the blank in a recess between the jaw and inner face of the back of
the carrier frame (see Figures 1 and 4). A soft steel plate or blank of a size
sufficient to form a number of saws rests at its lower end or edge upon a follower D
in the carrier. This follower is adjusted to regulate the width of the piece to be
projected above the carrier frame or vice to have the teeth formed thereon by means
of a screw D', working in a nut & on the follower. The elevating screw is suitably
supported in a cross piece d, at the lower end of the carrier frame, or in other
convenient way.
An indicator and adjusting wheel E, secured to the lower end of the screw D',

page_text: and a spring stop pin E¹ taking into the holes e of the wheel enables the operator
to regulate the screw, and consequently the upward feed of the blank, as desired, in
a way well understood. Inclined ways or cams e¹, e², (see full and dotted lines,
Figure 2), near the ends of and upon the under surface of the lower guide flange or
support of the carrier are provided for a purpose herein-after to be explained.
The blank carrier is fed forward step by step by a screw F, operated by a pawl f
and a ratchet wheel F¹ to which the screw is connected at one end of the sup-
porting frame. The feeding screw turns in suitable bearings in a hollow between
the upper and lower portions of the longitudinal projection or ledge B₁ at the side
of the frame upon which the carrier moves. A half nut or sectional female screw
f1 carried by a lever F2 pivoted upon the carrier, engages with the blank
traversing feeding screw.
When the movement of the carrier is to be reversed by hand, or it is desired to
stop the feed for any purpose, the nut is disengaged by rocking the lever outward:
Motion is imparted to the mechanism from a driving shaft G driven by power in
any suitable manner, a crank g for turning the shaft being shown in the Drawings
for the sake of illustration only An eccentric H on the main shaft encircled by
a strap or ring h in a well-known way communicates motion to the ratchet wheel
F¹ by means of a rod H¹ connected at one end to the ring and at the other to the
short arm of a crank lever pivoted at the juncture of its arms to the frame.
The long arm H of this lever works in a slot near the outer end of a vibrating
lever, turning loosely on the hub of the ratchet wheel. The pawl f is pivoted
to this vibrating lever, and is held up to its work when in operation by spring f³,
secured at its opposite ends respectively to the lever and pawl. The feed of the
screw F may be regulated by adjusting the connecting rod H¹ in any desired one of
the holes in the short arm of the rocking crank lever.
A cutter or chisel I is reciprocated in a guide way or socket I', the longitudinal
axis of the chisel being in or substantially in the vertical plane of the blank to be
operated upon, and the chisel reciprocating above and at an angle to the edge of the
blank corresponding to the inclination of the teeth. The reciprocating movement
is imparted to the chisel by a crank I on the end of the driving shaft, and a
pitman J connected with the chisel stock or holder J¹. The chisel is detaclrably
secured in its holder so that it may be readily removed.
By an inspection of the Drawings it will be seen that as the blank (the top edge
of which projects above vice or carrier) is fed forward the proper distance for
forming a tooth, the chisel descends at an acute angle to the blank and cuts into
its edge, and that as the chisel retracts the blank is fed forward another step to be
again operated upon by the chisel on its advance stroke to form a tooth. The
mechanism is timed in its movements so as to operate connectedly and cut a series
of teeth to form the saw. The metal to form the teeth is forced or pressed
from the edge of the blade as will be understood by an inspection of the Drawings.
To sever the saw blades from the blank gradually and during the time the teeth
are being cut, a cutter K (shown as of a circular form) mounted upon and turning
with a stud supported in an arm K', crosses the path of travel of the blank and.
severs a strip of the width of a saw from the blank as it is fed forward.
The edge of the cutter it will be observed is bevelled so as to cut with but little
resistance and slight strain upon the vice.
To leave toothless spaces at the ends of the saw blade the chisel is held out of
operation during the time the blank is at and near the beginning and end of its
traverse lengthwise of the frame and passed the chisel. The cutter for severing
the saw blades from the blank, however, continues in operation from the time the
blank first comes in contact with its edge at one end until it passes and clears it at
the other.
To leave the blanks at the ends of the blades the chisel guideway or socket I is
formed with or securely attached to a pivoted frame L, rocked or vibrated on a
pivot, by which it is secured to the projecting top portion of the main frame.
plate L' serves as a stop to limit the upward movement of the pivoted socket frame,
A

page_text: a shoulder or projection on the top of this frame abutting against the edge of the
plate when the frame is moved upward. A long plate or flap bar M, movable
endwise in a vertical recess or slot in the main projects downwards beneath the
frame at its lower end and carries a roller M¹ mounted and turning upon a shaft m
which projects through the bar. A spring m², secured at one end to the under side
of the frame acts upon the bar with a tendency to throw it upward the free end of
the spring bearing upon the shaft m. The inclines e¹, e2, (herein-after described) of
the blank frame or carrier and those parts of the flange b₁ from these inclines to the
ends of the frame allow the roller to remain in its elevated position as held by the
spring during part of the traverse of the blank, but when the deepened central or
downwardly projecting portions N of the flange strikes the roller and moves in
contact with it, the bar is drawn down, and the chisel frame depressed so as to
assume its operative position. A pin and slot connection (see dotted lines, Figure 2)
prevents binding or cramping between the bar and chisel frame as will be well under-
stood.
So far, I have only described mechanism suitable for cutting the teeth, feeding
the blank, and severing the saw blades, but in order to set or project the teeth
laterally alternately to the right and left as they are cut; when this is desired I
impart to the chisel an axial oscillating or rocking motion in its guideway or holder
so as to present the chisel to the edge of the blade in such manner that as one cut
is made it presses the metal forming the tooth out in one direction, and the next
cut forces the metal of the succeeding tooth in the opposite direction.
A doubled-pathed or two-way cam O is secured upon the main shaft and operates
upon the rounded or doubly inclined sides of a head P pointed at both ends so as
readily to pass from one to the other of the cam tracks o¹, 02, on either side of the
central flange of the cam. The stud p, to which the head P is fastened, or with
which it is formed, is mounted so as to turn freely in a sleeve or bearing p¹ in one
end of a pivoted lever or vibrating arm Q, supported on the frame by a pivot q,
shown as secured in the plate L. The opposite end of this arm is connected by
means of a universal joint with a lever secured to the chisel holder J¹. This joint
is shown as consisting of the arm R, having the balls 7, 71, one at each end, and
sectional sockets or bearings 1, 2, one at the end of the arm q and the other at the
outer end of the lever Q¹, fastened to the reciprocating chisel stock. To adinit of
the required oscillating movement of the chisel its holder is connected with the
pitinan J by means of a swivelling coupling S (see Figure 5). The pivots q may
be changed from one to another of the holes in the arm and its corresponding
hole in the plate L to rock the cutter more or less according to the "set" it is
.desired to give the teeth.
From the foregoing description it will be obvious that as the blank or saw blade
T, Figures 4, 7, 8, 9, and 10, is moved forward in a fixed path or straight line
beneath the chisel, the teeth will be cut and formed as shown (see Figure 11) with
the teeth set and properly bevelled. Figure 7 represents a deep cut as being made,
the surplus metal displaced at one cut being removed by the succeeding cut or cuts.
Figure 8 shows but a slight amount of metal removed, and Figure 9 represents a
light cut where no metal is removed. This latter method of forming the teeth I
deem preferable. At cach retraction of the chisel it is rocked to properly present it
to the blank, and at the same time the blank is fed forward the required distance
*for the next cut.
By my improvements it will be seen that a single chisel is made to form a saw
blade complete from a blank and ready to be tempered, thus dispensing with setting
and sharpening separately. It is also apparent that both time and labor are saved
by the employment of a blank large enough to make a number of saws, and auto-
matically severed into blades.
Obviously modifications may be made in my improvements without departing
from the spirit of my Invention; for instance, the mechanism may be arranged
horizontally or at an inclination instead of vertically as shown; the saw blank
carrier might automatically be returned to the starting point after forming a series

page_text: of teeth on and severing a saw from the blank; different sized cams might. be
employed for increasing or lessening the throw or amount of endwise movement
of the chisel; the feed of the blank upward in the vice might be accomplished
automatically after the cutting of each blade therefrom ready for the operation of the
chisel upon the next, and various changes may be made in the details of the
mechanism; the carrier might be traversed by a long rocking arm.
The blades
would thus be severed on a slightly curved line.
If it is not desired to give a "set" to the teeth the following method and
mechanism may be employed.
Plate III., Figure 12 is a side elevation; Figure 13, a plan or top view;
Figure 14, a bottom or inverted plan view, partly in section through the frame
supports on the line 1, 1, of Figure 12; Figure 15 is a view partly in clevation and
partly in vertical transverse section on the line 2, 2, of Figure 12, showing the blank
feeding and clamping devices.
Plate IV., Figures 16, 17, 18, and 19, are diagrams on an enlarged scale, showing
the method of cutting the teeth in the blades; and Figure 20 a plan or edge view
of a portion of a toothed blade.
A stout frame A supported upon a proper base or supports A¹, A, is provided
with suitable bearings for a driving shaft B at one end. This shaft is driven by power
in any suitable way. A hand crank b for revolving it being shown in the Drawings
for the sake of illustration only. A crank a upon the end of the shaft opposite to
that upon which the hand crank is secured drives a pitinan B', which is jointed at its
outer end to one end of a rocking arm or vibrating lever C, the opposite or lower
end of which lever is suitably pivotted to render it capable of being rocked freely by
the pitman. A cutter or chisel C¹ secured to this vibrating lever at its upper end;
and projecting outward and downward therefrom, cuts the saw teeth in the blank,
as will herein-after be explained.
The vibrating lever C is pivoted at d near the free end of a vibrating arm D, in
turn pivoted at d to the under side of the frame or to a down hanger D projecting
therefrom. A strong spring E secured at one end to the bottom of the frame bears
upward at its opposite end upon a stud e on the arm D, thus acting with a tendency
to force up this arm and consequently the chisel lever C. A roller E¹ upon the
outer end of the arm D is in this way constantly pressed against an annular cam f
formed upon the projecting under side of a pinion F meshing with a worm wheel G,
turning with a shaft E mounted in suitable bearings g, g', beneath the frame:
This shaft G is shown by the Drawings as driven from the driving shaft B by a
band H, but it may be driven by any suitable gearing. This band passes from a
pulley Hon the driving shaft to the pulley on the worm wheel shaft. The
pinion F, driven by the worm wheel, is fast upon an upright shaft I turning in
bearings in the frame, to which shaft is likewise secured a pinion I¹ meshing with a
corresponding pinion J upon a shaft J parallel with the shaft I. This shaft. J' is
mounted in suitable. bearings in a bracket frame or housing K at the side of the
supporting frame. Each shaft carries a feeding roller or dise K1, K2, at its upper
end, the adjacent surfaces of their peripheries nearly touching. The roller K can
be brought close to or allowed to recede from the roller K2 by means of any suitable
adjusting device, such for instance as the set screw which passes through the
bearing and abuts against the shaft at its point. The shaft is allowed sufficient
lateral play in the bearing to admit of the requisite adjustment of the space between
the rollers to suit the thickness of the blank to be acted upon.
An adjustable anvil or support L for the saw blank, and upon which the lower
edge of the blank bears is provided with a gauge or indicator L' (see Figure 12) by
which to regulate the width of strip to be cut from the blank. This anvil slides
endwise through the blank guideway formed by a recess or opening m in the
bracket. frame K (or between the bracket and supporting frame), see Figure 15, and
the lower inclined edge of the anvil rests and is firmly supported at or near one end
upon a correspondingly inclined edge or shoulder M at the bottom of the guideway.
The opposite end of the anvil is supported and the anvil adjusted and held as

page_text: desired by a screw cap or nut m¹. The anvil may be slid endwise on the screw
stud which passes through the elongated slot M'. The blank is fed forward in the
guideway or recess m through which it is traversed endwise. A cutter N, shown
as composed of a revolving disc mounted upon a stud n in an arm O secured upon
the top of the frame serves to sever strips from the blank as they are being toothed
by the passage of the blank to and past the tooth cutter or chisel C. An arm Q
which may be turned out if desired is mounted upon the top of the bracket frame K
and bears upon the side of the blank, thus preventing the curling or winding up of
the blade as it is cut from the blank.
The chisel C¹ (see Figure 19) has a central slit or opening p in its point or
cutting end, of a width about corresponding to the thickness of the blank or saw
blade to be operated upon. As the chisel cuts into the edge of the blank, the teeth
are formed in part by raising or forcing up the metal of the blank, the surplus
metal, if any, crowded out or displaced by one cut being sheared off by the suc-
cceding cut or cuts, the blank being fed forward during each retraction of the chisel
a proper distance to be acted upon at its next descent.
Figure 16 represents the chisel as making a deep cut, all the surplus metal
crowded backward and upward by one cut being removed by the next, and the
points of the teeth terminating in line with the edge of the blank. In Figure 17
the cut is not so deep, and the teeth, as formed, project slightly above the edge of
the blank; and Figure 18 represents a shallow cut, that which I prefer. In this
last Figure no metal is removed or cut off, the teeth being formed wholly by
displacing or forcing upward and backward the metal of the blank to form each
tooth.
The formation of rough edges or burrs at the sides of the teeth is prevented as
will be apparent from the Drawings, by the chisel which straddles the blank edge
and cuts close to the sides of the blade.
From the foregoing description it will be apparent that the chisel reciprocates in
a slightly curved line as its carrying arm C is rocked by the pitman from the
driving shaft. The saw blade or blank is fed regularly to the chisel and shearing
cutter by the feed rollers or wheels K¹, K At proper intervals the chisel is
thrown out of operation by means of the cam f on the pinion F, the roller E¹ on the
end of the vibrating arm D running alternately in contact with the recessed or cut
away part and regular or raised portion f2 of the cam. When in contact with
the latter part of the cam, the cutter is held down to its work so as to strike the
blank at each stroke, but when in contact with the depression or cut-away face of
the cam the chisel is elevated. In this manner toothless spaces are left at the ends
of the blank and between each series of teeth to form the separate blades.
Obviously the blank may be severed into lengths to form blades, by a cutter carried
by one feed roller and working in a recess or nick in the periphery of the other, or
other automatic severing device may be employed.
It is manifest that a considerable saving in both time and labor is effected by
cutting the teeth in series upon a single blank, as described, to form a number of
saws at a single traverse of the blank, and that by automatically throwing the chisel
out of operation at proper intervals, unnecessary wear and tear upon the machinery
which would result from the continuous action of the chisel throughout the length
of the blank is avoided.
Obviously my improvements may be modified to some extent without departing
from the spirit of my Invention. For instance, different cams designed to throw
the cutter out of operation at longer or shorter periods may be employed, and the
arm D adjusted lengthwise by means of a series of holes, through any one of which
the pivot might be passed so as to cause the roller E to work upon the desired
cam; or other well known means of adjustment might be employed.
The anvil may be fed up automatically after the severing of a strip. The
blank may be run back by reversing the revolution of the driving shaft, or by hand.
I claim as my Invention,-
First. The herein-before described improvement in the art of manufacturing saw

page_text: blades, which consists in forming the teeth successively by cutting the saw blade
from the edge inward towards the centre or back at an acute angle, and pressing
out the teeth sidewise alternately to the right and left, substantially in the manner
set forth to cut and set the teeth simultaneously.
Second. The herein-before described improvement in the art of manufacturing
saw blades by machinery, which consists in cutting the teeth upon the blank by
successive cuts of a chisel operating in the plane of the blank, reciprocating in a
path at an acute angle to that traversed by the blank, and acting upon its edge
to displace or force up the metal thereof to form the teeth, substantially in the
manner described.
.
Third. The combination, substantially as herein-before set forth, of a saw blank
carrier traversed step by step in a fixed path, and a chisel reciprocating at an
acute angle to and in the plane of the blank, whereby the teeth are formed by
forcing up or displacing the metal at the edge of the blank by cutting from the
edge inward, as set forth.
Fourth. The combination, substantially as herein-before set forth, of a traversing
saw blank carrier, a reciprocating chisel, and the blank severing cutter, whereby a
strip to form a saw blade is gradually severed from the blank as the teeth are being
cut on its edge by the chisel.
Fifth. The combination, substantially as herein-before set forth, of a traversing
saw blank carrier, a reciprocating chisel acting upon the edge of the blank to cut the
teeth, and the adjustable chisel carrying frame automatically elevated and depressed
to throw the chisel out of operation at the ends of the blank and holding it in
working position to cut the teeth centrally upon the blank.
Sixth. The combination, substantially as herein-before set forth, of the supporting
frame, the blank carrier traversing endwise thereof, and in which carrier the blank
is clamped and adjusted, the chisel for cutting the teeth and the cutter for sheering
the blades from the blank above the carrier.
Seventh. The combination, substantially as herein-before set forth, of the blank
carrier, the reciprocating chisel and mechanism, substantially such as described for
axially oscillating the chisel in its guideway to alternately press the teeth in
opposite directions as they are cut in the edge of the blank, as set forth.
Eighth. The combination, substantially as herein-before set forth, of the pivoted
chisel carrying frame, the chisel reciprocating therein, the pitman connected with
the chisel holder by a swivelling joint, the vibrating arm actuated by a cam on the
driving shaft, and the universal joint connection between said arm and an arm on
the chisel holder whereby the chisel is reciprocated and rocked axially, and its
frame left free to be elevated and depressed to throw the chisel out of and into
operation.
Ninth. The combination, substantially as herein-before set forth, of a guideway for
the saw blank and a reciprocating chisel operating upon the edge of the blank and
automatically thrown into and out of operation at intervals to form series. or
different sets of teeth with intervening untoothed spaces whereby a number of blades
are toothed at a single traverse of the blank.
Tenth. The combination, substantially as hercin-before set forth, of the recipro-
cating chisel and the saw blank feeding rollers by which the blank is presented to
and firmly held against the thrust of the chisel reciprocating at an acute angle to
the edge of the blank above the rollers to successively cut the teeth thereon, as set
forth.
Eleventh. The combination of the saw blank clamping and feeding rollers, the
cutter for severing the blank longitudinally into strips to form saw blades, and tho
reciprocating chisel for toothing the blank edge, these members being constructed
and operating substantially as herein-before set forth.
Twelfth. The adjustable endwise moving anvil for supporting and adjusting the
saw blank, substantially as set forth.
Thirteenth. The combination, substantially as herein-before set forth, of a guide-
way in which the blank is traversed, a chisel operating upon the edge of the blank

page_text: and reciprocating above in the same plane as and at an inclination to the blank,
and an anvil adjustable in the blank guideway and supporting the blank.
Fourteenth. The combination of the chisel reciprocating above the traversing saw
blank, the rocking lever to one end of which the chisel is secured, the vibrating arm
to which said lever is pivotted at its opposite end, and a cam operating upon the
said vibrating arm, these members being constructed and operating substantially as
herein-before set forth to automatically throw the chisel into and out of operation.
In witness whereof, I the said Sydney Pitt, have hereunto set my hand
and seal, this Eleventh day of July, in the year of our Lord One thousand
eight hundred and seventy-seven.
SYDNEY PITT. (L.S.)