Improvements in Saw Sharpening Machines.
Year: 1889

page_text: Improvements in Saw Sharpening Machines.
1, FRIEDRICH SCHMALTZ of Offenbach in the Empire of Germany, manufacturer,
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 :-
.:
The present invention relates to improvements in machines for the automatic
sharpening of band-, circular-, or other saws.
The sharpening medium is an emery wheel or disc, which is arranged in an
inclined position and has imparted to it a rotary and an up and down motion. This
emery wheel acts with its face upon the lower edge of the saw tooth while it (the
said wheel) is being lowered and with its periphery upon the back of the tooth while
the saw is being moved forward.
The principal movements of the machine are ;-
1, the up and down movement of the revolving emery wheel or disc.
2, the forward movement of the saw to be sharpened.
3, either an oscillating movement of the saw blade, or a backward and forward
movement of the emery wheel or disc with a simultaneous movement round its
vertical axis.
By means of these movements the alternating cutting and back edges of the
teeth are operated upon.
The different parts of the machine producing these movements are adjustable
relatively to each other in such a manner that they can be adjusted to any form of
tooth the saw may have.
In the accompanying drawings ;-
Figs. 1 to 11 represent a machine with an oscillating saw and in Figs. 1* to 6* i
represented a machine with a reciprocating and revolving emory wheel or disc.
Of Figs. 1 to 11 Fig. 1 represents a front elevation, Fig. 2 a side elevation, Fig. 3
a rear end elevation and Figs. 4 to 11 details all hereinafter more particularly described.
The emery wheel or disc carried in the arm C which is mounted on centres in
the standard D receives its motion from a grooved pulley F on the driving shaft
by means of a cord or the like passing over guide rollers. The arm C with its bear-
ings is mounted adjustably on the standard D so that any desired vertical inclination
can be given to the emery disc.
The driving shaft further drives a shaft a by means of a cord or equivalent on
which shaft are mounted the two crank discs A B. By means of the crank disc A
the saw is moved forward and by means of the disc B the up and down motion of
the emery disc is effected. The crank pin on the disc B by means of a connecting
rod or link raises and lowers, the lover pivotted to a bracket or to the frame E of
the machine. This lever is connected with the elongation of the arm C by
means of a chain h¹ so that when the lever is raised the emery disc will be lowered
by its own weight, and when the lever is lowered its chain h¹ will draw down the
part of the arm C and thus lift the emery disc at the other end of the said arm.
The crank pin is adjustable in a slot of the disc B and in this manner the stroke of
the arm C and the emery disc can be adjusted to the depth of the teeth of the saw
to be sharpened. In a similar manner the crank pin of the disc A effects the forward.
movement of the saw blade by means of a lever, connecting rod and a pawl which
engages with the teeth of the saw. During one half of the revolution the pawl slips
over the back of one tooth and falls into the recess between the said tooth and the
tooth next to it and during the other half of the revolution the pawl moves the saw
blade forward. This crank pin is adjustable in a slot of the disc A so that the stroke
of the pawl can be regulated according to the size of the teeth of the saw to be

page_text: sharpened. The disc A is further mounted on the shaft a in such a manner that it
can be adjusted thereon so as to be able to regulate the time of the lifting of the
emery disc in reference to the forward movement of the saw blade. By the provision
of these three adjustments the machine can be adjusted to all forms of teeth.
To produce the reciprocating movement of the saw, the mechanism by which the
saw is held is mounted on a vertical eccentrically turning rod f. Straight saws are
held in a frame or carriage G (Fig. 4) which slides on the rail b. The rail b can
be adjusted vertically according to the width of the saw blade by means of the
parallel motion b c d fig. 4 and is held in the right position by a binding screw or
equivalent means. The whole mechanism is removably attached to the rod fl by
means of a strong strap d'. Circular saws are simply placed on a horizontally pro-
jecting pin or spindle (Fig. 6) and jammed on a conical ring f. This arrangement is
mounted so as to be vertically adjustable on the rod fl.
The axis round which the rod f turns must be in the same line with the middle
plane of the saw blade and for this purpose the rod f¹ is mounted at the top with
a segment on the standard f³ fixed to the frame E, on which standard the segment
can slide, and at the bottom it ends in a short crank capable of being turned in a
socket. The rod is arranged to one side of the plane in which the emery disc
oscillates so that the saw reciprocates under the emery disc when the rod f' is turned
to and fro. By these means the saw is placed alternately to the right and left slant-
ingly to the emery disc; and in this manner the face of the emery disc sharpens and
forms the sides of the teeth, while the periphery thereof sharpens the back of the teeth.
As the cutting edges of the teeth are on alternate sides of the saw (Fig. 11), this latter
must be suddenly reversed at the moment when the emery disc leaves the back of the
tooth i.e. after every complete revolution of the shaft a.
This sudden movement of the rod f is produced by means of the shaft i driven
by suitable gearing from the shaft a and only making half a revolution while the
shaft a makes a complete one. On this shaft is mounted a crank disc J the crank
pin of which engages with the curved grooves of the cam plate K (Fig 10). This
cam plate is constructed in such a manner that the crank pin p in its way from 1 to 2
and from 3 to 4 moves the plate K suddenly to one side, the said plate remaining
stationary during the travel of the pin p from 2 to 3 and 4 to 1, the guide grooves
2-3 and 4-1 being segments of a circle having the same radius as the circle in
which the crank pin p moves. To the cam plate K is fixed an arm K' which com-
municates motion to another arm K by means of the pin O this arm K being fixed
to the rod. The pin O is adjustable in slots in the arms so that a larger or smaller
movement can be communicated to the arm K' and the rod f1 thus placing the teeth
of the saw more or less oblique to the emery disc.
The part in which the upper end of the rod is mounted, is provided with an
elongation (Fig. 7). In a groove of this elongation can be moved a wedge by
means of the screw fin such a manner that the saw blade wbich bears on this wedge
can be adjusted according to its thickness exactly to the axis round which turns the
rod f.
The saw is held against this device by means of the holder 10, the bolt f
and nut (Fig. 5) and the arm f which can turn on fo. The parts 10 and have
oblique contact surfaces which are pressed together by the nnt. By a proper
adjustment of the arm and subsequent screwing down of the nut the former can
be so adjusted and held that it bears with the necessary pressure on the saw blade
without preventing a uniform steady forward movement of the latter.
On the arm C is an arrangement for finely adjusting the emery disc relatively to
the saw blade. The elongation h² is pivotted to the arm Cat and forms with
the latter a bent lever adjustable by means of the screw . By turning this screw
the arm C can be lifted or lowered to finely adjust the position of the emery disc or to
compensate for the wearing out thereof."
For temporarily removing from action the emery disc and the mechanism for
moving forward the saw blade the following arrangement is made; In the block D
(Fig. 7) is supported a short shalt g¹ upon one end of which is mounted the hand
wheel and the cam or arm g³ and on the other end the rigidly fixed tappet or

page_text: lifter and the loose lever 9. When the hand wheel is turned the cam or
arm g engages with a nose 9 under the arm C and lifts the forward end of the
latter and maintains it in this raised position, while the pawl is removed from the
teeth of the saw by the lever g. When the hand wheel is turned back to its original
position the arm C and the pawl r are again lowered.
The machine is further provided with an arrangement to move the first tooth of the
saw to the pawl in the right inclination.
q
A lever is connected with the arm K¹ (Figs. 6 and 8) by means of the pin q¹.
This lever is pivotted on a pin q3 adjustably fixed to the frame E and carries at its
upper end the hinged arm 9. By adjusting the pin 3 in the slot q the stroke of
the lever g can be regulated according to the space between the teeth of the saw.
The modification represented in figs. 1 to 6 differs from the above described
construction in so far as here the saw does not reciprocate and the emery or other
grinding wheel is canted to the right and left besides being moved up and down.
Fig. 1 is a front elevation of this modified machine, of which
tudinal section, and Fig. 3" a rear end elevation. Fig. 4 is a
mechanism for imparting the canting movement to the emery disc.
a modification of the manner of mounting the rod f.
Fig. 2* is a longi-
plan of the lever
Fig. 5* represents
The crank discs A and B produce as before the forward movement of the saw and
the up and down movement of the emery or sharpening wheel or disc. The rod f
carrying the saw-holding mechanism is here stationary. The arm C in this construc-
tion is of a somewhat modified form. The emery disc with its spindle is not
journalled in the arm C but is hung in it so that it can turn round a vertical axis.
In the middle the arm is forked and is mounted on the spindle w which is
supported between centres by the standard D' which with its support D) is mounted on
the carriage S capable of sliding on the frame E so that the arm with the emery or
sharpening disc participates in this movement. Instead of the shaft i described in
the preceding arrangement, the shaft is here driven from the shaft a by means of
bevil gear, and on this shaft as shown in fig. 2 is mounted a cam which revolves
within a rectangular frame of the rod K³ and imparts to the latter a jerky recipro
cating motion. The rod K³ moves the lever K pivotted at k¹ and this pivot is
adjustable so as to regulate the stroke of the upper end of the lever K. This upper
end is provided with a nut and hand wheel M through which passes the screw threaded
end of a rod m coupled to the carriage S. By turning the nut M the carriage can be
so adjusted that in its middle position the axis of rotation of the emery wheel stands
exactly above the saw blade and so that during the travel of the carriage corre-
sponding points will always come in contact with the teeth of the saw and give them
a uniform inclination.
For alternately canting over the emery disc the following mechanisin is provided;
upon a pin s (Fig. 4) fixed to the carriage S pivots the angle lever L' the short arm
of which is provided with a toothed segment which gears with a similar segment of a
lever L turning on the pin s¹ also fixed to the carriage S. The free end of the lever L
is forked or slotted and embraces a pin Q fixed to the frame E so that during the
movement of the carriage the lever L is turned round its pivot s. The pin Qis
adjustable in the slot of the lever L by means of a set screw Q' so as to be able to
regulate the stroke of the levers L and L. Qis an arm fixed to and projecting from
the frame E and formed with a groove for the reception of the pin Q.
The standard D' carries an arm R pivotted on the pin d¹ the upper end of which
arm engages with a slide block in a groove of a nut t sliding on the spindle w.
A pin secured on this slide block extends through the head of the arm R and there
carries a ring u which is held between centres in the forked end of the arm i con-
nected with the lever L'. By the oscillation of the lever L' the nut t is reciprocated
on the spindle w the block being arranged so as not to interfere with the up and
down movement of the emery disc. In the groove of the nut there also engages
another slide block of an angle or bell-crank lever U U mounted on the arm C which
lever is oscillated by the movement of the nut t and imparts an alternate left and right
movement to the emery disc round its vertical axis vol by means of the connecting

page_text: rod z. This turning takes place simultaneously with the reciprocating motion of the
carriage S it being produced by such motion.
The shafts a and are arranged so that a makes a complete revolution while i¹
makes only half a revolution i.e. while the saw is moved to the extent of one tooth,
the carriage S makes either a forward or a backward movement, the cam I¹ being so
mounted that it effects the canting of the emery disc just when the disc has passed
over the back of one tooth and is about to descend again. It is evident that the
before described arrangement of the cam plate could be employed instead of the
cam I.
In figs. 4 and 5" is represented an arrangement for lifting the saw to allow for the
wearing away of the emery disc; instead of lowering the latter as hereinbefore
described. The rod for this purpose is mounted in a little support and can be
moved by up and down by means of the screw to.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what I
claim is :-
1. In a saw-sharpening machine a crank disc such as B carrying an adjustable
crank pin by means of which a revolving emery or equivalent disc adjustable to any
desired angle and mounted in an arm can be moved up and down by means of a
connecting rod and a lever substantially as herein described and illustrated in the
accompanying drawings.
2. In a saw-sharpening machine a crank disc such as A mounted on the same shaft
as the disc B and adjustable in relation to the said disc B the disc A being also
provided with an adjustable crank pin which actuates mechanism engaging with the
teeth of the saw for moving it forward substantially as herein described and illustrated
in the accompanying drawings.
3. In a saw sharpening machine a rod or shaft such as farranged on one side of
the plane of oscillation of the emery or sharpening disc which rod f1 carries the
mechanism in which the saw is held and receives a jerky reciprocating motion from
suitable gearing driven from the shaft a substantially as herein described and
illustrated in the accompanying drawings.
4. In a saw-sharpening machine a carriage such as S arranged under an arm such
as carrying an emery or equivalent sharpening disc and to which carriage a jerky
reciprocating motion is imparted from the shaft a by means of lever arrangement
which motion together with the movement of the carriage cants over the emery or
equivalent disc operating substantially as and for the purpose herein described and
illustrated in the accompanying drawings.
5. In a saw sharpening machine a cam plate such as K in combination with arms
such as K K for the production of the jerky motion of the rod or shaft and a
pin such as o adjustable in the said arms for regulating the extent of such motion
substantially as herein described and illustrated in the accompanying drawings.
6. In a saw sharpening machine the combination with an arin such as C of an
elongation such as jointed thereto and screw such as for the purpose of vertically
adjusting the position of the emery or sharpening disc substantially as herein described
and illustrated in the accompanying drawings.
7. In a saw sharpening machine the mechanism such as described for taking the
emery disc and the saw feeding device out of action consisting essentially of an arm
or cam such as g³ mounted on a shaft such as g¹ on which are also mounted a tappet
or lifter such as g' and a loose lever such as g substantially as herein described and
illustrated in the accompanying drawings.
8. In a saw sharpening machine the arrangement for feeding to the sharpening
disc or wheel the first tooth of the saw in its proper inclined position consisting of the
lever 9. with its hinged arm q' the said arrangement being actuated by the mechanism
which imparts the reciprocating motion to the rod f¹ substantially as herein described
and illustrated in the accompanying drawings.
9. In a saw sharpening machine the combination with a cam such as I' operating

page_text: a rod or shaft such as K' of a lever such as K' for reciprocating the carriage also
the arrangement of the adjustable pivot k¹ and the nut M on the lever K' for regu-
lating the extent of such reciprocation substantially as herein described and illustrated
in the accompanying drawings.
10. In a saw sharpening machine an arrangement of mechanism for canting over
the emery or other sharpening disc consisting essentially of gearing such as L L'
and an angle or bell-crank lever such as U U connected through a nut such as t in
such a manner that the lever U U₁ can move up and down with the arm C and still
remain in constant connection with the gearing L L' substantially as herein described
and illustrated in the accompanying drawings.
11. In a saw sharpening machine the combination with a lever such as L of an
adjustable pin such as Q for the purpose of adjusting the extent of the motion to be
transmitted by such lever to the sharpening disc substantially as herein described and
illustrated in the accompanying drawings.
12. In a saw sharpening machine mechanism for holding straight saws consisting
essentially of a carriage such as G on a rail such as b which latter can be vertically
adjusted by means of a parallel motion substantially as herein described and illustrated
in the accompanying drawings.
13 In a saw sharpening machine the arrangement of a support such as x and screw
such as W between the rod f' and the frame E for the purpose of finely adjusting
the vertical position of the saw substantially as herein described and illustrated in the
accompanying drawings.
14. In a saw sharpening machine adjustable mechanism for bearing against the saw
consisting essentially of a wedge shaped slide block such as f adjustable by means
of a screw and a bearing arm such as fresting with an oblique face on the oblique
face of a holder such as f10 by which means the pressure of the arm on the saw
can be adjusted substantially as herein described and illustrated in the accompanying
drawings.
L 10th 13 1000
W. P. THOMPSON & BOULT,
Agents.