Improvements in Saw Grinding Machines.
Year: 1894

page_text: Date of Application, 15th May, 1894-Accepted, 16th June, 1894
COMPLETE SPECIFICATION.
Improvements in Saw Grinding Machines.
I CHARLES CLARK NEWTON of 2018 Mount Vernon Street in the City and
County of Philadelphia, State of Pennsylvania one of the United States of
America Mechanical Engineer do bereby declare the nature of my invention and
in what manner the same is to be performed to be particularly described and
ascertained in and by the following statement:-
The object of my invention is to construct a machine for grinding saws which
will automatically feed the teeth of the saw to the grinder and in which the
grinding tool will be traversed across the face of each tooth.
Referring to the accompanying drawing:
Figure 1, is a side view illustrating my improved saw grinding machine
Figure 2 is a lace view
Figure 3 is a plan and
Figure 4 is a sectional plan the section being taken on the line 4-4 Figure 1.
A is a standard, on the face of which is an undercut guide way A¹, clearly
shown in Figure 4 and adapted to this guideway is a slide B, flanges 6 of which
are adapted to the undercut edges of the guideway, on the back of this slide is a
screw threaded lug b' adapted to which is a feed screw B' held in position
longitudinally in a lug 62 on the standard A of the machine. The head of this
screw is shaped to receive a wrench so that the screw can be turned and thus
elevate or lower the slide B; ou the slide is a stud B2 on which is mounted the
saw to be ground, this saw is held in position on the stud by a cap b³ so that while
it is supported by the stud it can freely turn thereon.
Adapted to a slideway in the head of the standard A is a carriage D, which
carries the grinding tool d and also the driving shaft E of the machine, the driving
belt from a counter shaft passes around a belt pulley e on the shaft E and on the
shaft adjacent to this pulley is a larger pulley el around which passes a belt to a
pulley on the shaft E' carrying the grinding disc d, this grinding disc is secured
to the shaft by a nut and is bevelled to conform to the shape of the tooth, as
shown clearly in. Figure 2.
On one end of the driving shaft E is a pinion f engaging with a gear wheel F
mounted on a stud F1 projecting from the carriage D and on this gear wheel is a
crank pinto which is connected a rod E2 pivoted to a stud f' on the standard A
so that as the shaft E is rotated the gear wheel F will be turned and as this gear
wheel is on the carriage and its crank is connected by the rod E* to the fixed
stud the carriage will slide on the standard A and the grinding disc d will travel
across the face of the teeth of the saw while the said disc is being rotated by the
means described.
The portion of the saw acted upon by the grinder is held laterally be two
screws gg (Figure 1) one on each side of the saw which screws can be set to the
thickness of the saw, so as not to interfere with the feed of the saw from one tooth
to another.
The saw is fed to the grinding disc in the following manner during the intervals
the disc is clear of the saw.
Projecting from the standard A is a bracket A in which is a rock shaft I
carrying an arm I' which is adjustable on the said shaft, this arm has a slot i
through which passes the end of the shaft I and on which is a block i adapted to
the slot, the shaft being secured to the arm I', after adjustment, by a nut i².
One end of the arm I¹ is forked forming two fingers 12 extending one on each
side of the saw blade, as clearly shewn in Figure 4, and pivoted to these fingers are

page_text: discs carrying friction material it a bolt extends through the two fingers and
is provided with a nut j' so that more or less friction can be applied by turning
the nut.
I preferably make the fingers of spring metal, but I do not wish to limit myself
to this construction.
On the rear end of the shaft I is a slotted arm H connected to the slotted arm k
of a bell crank lever K by a connecting rod H which is adjustable on both arms;
the other arm k of the bell crank lever K has a friction roll against which
strikes a lug or cam surface D' secured to the carriage D; the bell crank lever K
is pivotted to the standard A and has an arm ³ extending through the standard to
the opposite side of the machine where it is provided with a weight K³ as shewn in
Figure 2 which keeps the roller k against the lug or cam surface D', a spring may
be used in place of the weight if desired.
When the carriage D moves back and the grinding disc is clear of the saw, the
lug or cam surface D' strikes the arm of the bell crank lever moving said lever
in the direction of the arrow (Figure 2) and consequently the arm I' is moved in
the direction of its arrow, moving the saw the distance required.
In order to prevent the saw returning with the friction feed dises 2ª I provide on
a bracket S secured to the standard A a pawls which engages with the teeth of
the saw as shewn in Figure 2. This pawl also, insures the proper relation of the
saw to the grinding disc d as the friction feed will keep the saw hard against the
pawl.
To accommodate teeth of different sizes I mount the pawl s on a block s¹ which
can be adjusted by means of a feed screw & in the bracket S towards and from the
grinding disc.
On the pawls is an adjustable hanger & carrying a supplemental pawls which
engages with a tooth at the rear of the pawls so that in the event of a saw having
one or more broken teeth being mounted in the machine one or other of the pawls
will hold the saw and prevent it returning with the friction feed.
The operation of the machine is as follows.-
The saw is mounted on the spindle B2 and the pawls ss3 are set to the teeth of
the saw so, that the grinding disc will align with the teeth, the friction feed is
adjusted and the machine set in motion.
The grinder will pass across the face of a tooth and on its return the lug or cam
surface D will operate through the bell crank K the friction feed, turning the
saw one tooth, each pawl s and s³ will engage a tooth and thereby prevent the
return of the saw with the friction feed, and the grinder will again traverse across
the face of the saw and grind the next tooth and so on until all the teeth are
ground.
The grinding disc cau be made of different shapes, the shape shewn in the
drawing grinds the face of the tooth as well as the inclined back.
On the carriage D is a rest M for a tool for trimming the grinding disc, this is
secured to the carriage by bolts m which pass through a slot in the shank of
the rest.
During the trimming of the disc the connecting rod E' is detached from the
crank and I may make the end of the rod forked as shewn in Figure 1.so that it
can be readily detached from the crank without removing the screw.
. Having now particularly described and ascertained the nature of my inven-
tion and in what manner the same is to be performed I declare that what I
claim is..
1. In a saw grinding machine the combination of the spindle for the saw the
grinder, a friction feeding device for feeding the saw forward and a pawl for
stopping the return of the saw with the feeding device substantially as hereinbefore
described.
2. In a saw grinding machine the combination of the spindle on which the saw
is mounted the friction feed consisting of an arm having two fingers clamping the

page_text: saw, a pawl for preventing the return of the saw with the friction feed and a.
grinder adapted to traverse across the face of the saw, substantially as hereinbefore
described.
3. In a saw grinding machine the combination of the spindle for the saw, the
vibrated arm I friction discs on said arm bearing against the saw, pawla engaging
the teeth of the saw to prevent the return of the saw with the friction feed, a
sliding carriage carrying a grinder adapted to grind the teeth of the saw, and a
lug or cam surface on the carriage acting upon the friction feed mechanism,.
substantially as hereinbefore described.
4. In a saw grinding machine the combination of the spindle for the saw, the
vibrated arm II carrying devices adapted to come into frictional contact with the
saw and move the same, a vibrated shaft on which the said arm is mounted, a bell
crank lever connected to the said shaft a reciprocated carriage carrying the
grinding tool, a lug or cam surface on the said carriage adapted to strike one arm
of the bell crank lever and thus operate the friction feed substantially as berein--
before described.
5. In a saw grinding machine the combination of the support for the saw, the
grinding tool adapted to pass across the face of the saw, a vibrated feed arm.
having two fingers one on each side of the saw, friction discs mounted on the said
fingers, with means for adjusting the discs so as to increase or diminish the friction:
substantially as hereinbefore described.
6. In a saw grinding machine the combination of the support for the saw, the
friction feed mechanism, the grinding tool, a stop pawl adjustable towards and from
the grinding tool, substantially as hereinbefore described.
7. In a saw grinding machine the combination of the support for the saw, the
friction feed mechanism, the grinding tool, the pawl a mounted on a block s¹ the
said block being adjustable towards or from the grinding tool and a supplementary
pawl substantially as hereinbefore described.
8. In a saw grinding machine the combination of the spindle for the saw, a
vertically adjustable slide carrying the said spindle, a screw for adjusting and
locking the said slide, a friction feed device for feeding the saw, a stop pawl for
the saw, a reciprocated carriage carrying the grinder and means for operating the
friction feed mechanism, substantially as hereinbefore described.
9. In a saw grinding machine the combination of the support for the saw the
feeding mechanism for the said saw a reciprocated carriage, a grinder mounted
thereon, a driving shaft mounted on the said carriage, and a crank and connecting
rod, the said rod connecting the crank to a fixed portion of the machine so that the.
carriage will be reciprocated substantially as hereinbefore described.
10. In a saw grinding machine the combination of the support for the saw
feeding mechanism, the grinding disc, a carriage on which the said disc is mounted,.
a driving shaft on the said carriage adapted to drive the grinding disc, a crank on
the carriage geared to the driving shaft, a rod connecting the said crank to the
fixed portion of the machine so that the driving shaft and grinder will reciprocate
with the carriage substantially as hereinbefore described.
Dated this 15th day of May 1894
JOHNSONS & WILLCOX,.
Agents.