Improvements in or relating to, and Means for, Grinding Iron and Steel and other Articles.
Year: 1893

page_text: Date of Application, 5th Sept., 1893-Accepted, 28th Oct., 1893
COMPLETE SPECIFICATION.
Improvements in or relating to, and Means for, Grinding Iron and
Steel and other Articles.
I, BENJAMIN WILLCOX of 47 Lincolns Inn Fields in the County of Middlesex
Patent Agent do hereby declare the nature of this invention (which has been
communicated to me from abroad by Allen Johnston, of Ottumwa in the
State of Iowa U.S.A. Manufacturer) and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement :-
This invention has reference to means for grinding articles of iron and steel
particularly tempered steel, such as tools, discs, knives, die blocks, and various
other articles whose surfaces require to be ground.
The object of the invention is to effect a great economy in the grinding of iron
and steel, and to accomplish industrial results which could not heretofore be
successfully attained by means of natural or artificial grinders. This object is
effected by the use of an artificial grinding wheel of cup-shape, adapted to contain
water and distribute it by centrifugal force over the grinding face or edge of the
wheel, and by the combination of such a grinder or emery wheel with various
devices for holding guiding and feeding the work, as hereinafter fully described.
The chief difficulty encountered in grinding hard steel arises from the great heat
generated by friction, which necessitates a slow and careful operation to avoid
drawing the temper of the steel and causing chips of steel to weld against the
surface of the grinder. This heat could be dissipated by a sufficient stream of
water but as emery grinders are now made (that is very compact, with the grains
close together) the water is in great part scraped off by the front edge of the article
being ground, so that but a thin film of water actually passes between the article
and the grinding surface.
This difficulty is completely obviated, according to the present invention, by
incorporating with the emery (or other abrading material) and the binding agent, a
substance which absorbs, or is soluble in water, which substance is dissolved out or
loosened from the surface of the grinder, leaving interstices or cells which are
occupied by the water during the grinding operation. This soluble or absorbent
substance is most advantageously applied in the form of grains, and common salt is
well adapted for the purpose in point of economy and efficiency. With a wheel of
this character a much deeper cut can be taken than with the grinding wheels
heretofore employed. Moreover, it will grind substances that cannot be practically
ground on artificial grinders, such for example as marble, granite or oil stone,
as well as steel, wrought iron, and cast iron.
The mode of preparation of the wheel varies according to the precise use for
which it is designed. If the article to be ground is narrow, say half an inch in
width, a comparatively small amount of water will be required between the article
and the grinder. For articles of greater width (say six inches and upwards) a
greater proportion of water with respect to the area of the surface acted upon will
be required, since in this case each particle of emery is in contact with the article
and subjected to friction a relatively long period of time. Provision for a greater
or less quantity of water is made by varying the proportions of the soluble
material or the size of the grains. Obviously the larger the grains, the larger will
be the spaces left for occupation of the water when the grains are dissolved and
washed out.
An ordinary wheel for common use in grinding steel is composed of emery six
pounds, shellac one pound, and salt one pound, but these proportions can be varied
within wide limits, and other binding agents can be used in place of shellac.

page_text: In preparing the wheel the shellac is rendered fluid by heat and the salt and emery
are mixed therewith. The wheel is then moulded in the ordinary way.
The
shellac, when in a melted state does not dissolve or destroy the granular character
of the salt.
The wheels made of this composition may be of any desired shape, but a ring or
cup shaped wheel or grinder is preferred, and is most suitable to the purposes of
this invention.
Heretofore in the grinding of articles having irregular or uneven surfaces,
automatic feeding devices have been used only to a limited extent, most of the
operations involved in finishing such articles being performed by hand. The blades
of pocket-knives may be taken as an illustration of the class of articles having
irregular and uneven surfaces.
To bring such a knife blade to its true shape by grinding it must be ground flat
on the side for a greater part of its length, and then gradually rounded off towards
the point. The back is also to be ground flat for the greater part of its length and
then rounded towards the point. When the blade is chamfered on one side, as
usual with large blades, there is a third operation involving an irregular feed.
One object of my improvement is to effect the grinding of these, and similar
irregular surfaces, by means of automatic feeding devices.
At present (unless the work is held and guided by hand) the sides of pocket
knife blades are usually ground by being fed and held against a rotating grinder of
greater thickness than the length of the blade. This simply grinds a flat surface
leaving the rounding of the blade towards the point to be finished by hand.
Another operation in the fashioning of pocket knife blades consists in forming a
shoulder near the end which is attached to the handle. In the manner in which
such blades (and other articles having a similar shoulder) are ground, the shoulder
cannot be properly cut by grinding, and must be finished by hand, the reason being
that the corner of the wheel which forms this shoulder is continually wearing away
and becoming rounded, the greatest amount of wear being directly on this corner.
One feature of the present invention consists in feeding the blade flatwise against
the wheel, grinding this shoulder first, and then feeding the blade lengthwise across
the grinding edge until the point of the blade is reached. By this method the
corner of the wheel which grinds the shoulder has no other work to do, and the
wear of the face of the wheel constantly tends to keep this corner sharp.
The invention includes mechanism whereby the operation indicated above may
be accomplished. The automatic feeding and work holding mechanism comprises
a slide by which the work is carried and which is capable of moving in any
direction in one plane, actuating mechanism for reciprocating the slide to grind the
flat surface, and a cam or former (whose shape is regulated in accordance with the
particular contour to be given to the work) for deflecting the slide in order to
grind the irregular or curved portion of the surface. In moving laterally towards
and from the grinding surface the slide may swing on a centre, or move bodily in
guides. The specific motions of the slide are, of course, relative to the grinding
wheel, and it is immaterial which of these devices is relatively movable.
Other improvements included in this part of the invention are fully hereinafter
described.
The invention further comprises automatic means for adjusting the wheel with
reference to the work holder. The arbor of the grinding wheel has heretofore been
made adjustable lengthwise by means of a hand wheel. According to the present
invention the wheel is moved forwards intermittently by automatic devices, the
amount of motion being sufficient to compensate for wear. Inasmuch as the
amount of wear will vary with the hardness of the steel or other material acted
upon, as well as with the composition of the wheel itself, the invention includes
means for regulating the amplitude of motion given to the wheel at each automatic
adjustment. The required amount of motion being ascertained and the adjusting
mechanism regulated accordingly, the workman has no further concern with the
adjustment of the wheel.

page_text: Preferably the mechanism is so constructed as to effect an adjustment at the end
of each complete movement of the work holding slide, and it is also preferred to
provide the machine with an automatic stop to arrest the feed mechanism at the end
of each movement. This is desirable because one workman in practice supervises
several of these machines, and unless very watchful he would not always be ready
to stop the machine and remove the work at the proper moment.
Heretofore, in grinding flat, concave, or convex surfaces, such as disc shaped
saws, or cutters, die blocks and the like, the practice has been to hold the article
against the edge of a grinding wheel, that is to say tangentially to the periphery of
the wheel, the wheel and disc or plate being rotated in planes substantially at right
angles to each other. The disc or other article is then fed across the edge of the
grinder so that the latter may act upon all parts of its surface, and in this operation
very great care and skill are required to produce an approximation to a true
surface, and to remove exactly the right amount of metal. As an example of
articles in this class to which the present invention is applicable, reference is made
to the small disc shaped cutters which are used for cutting slots in screw-heads and
for similar purposes.
These cutters are ground on both sides to a slight concavity
so that they are thicker at their outer edges than at the centre. By the present
practice of grinding this disc cutters, the expense of the grinding constitutes more
than eighty per cent. of the total cost of manufacture of the article; whereas by
means of the method and system of grinding herein described, the cost of grinding
is less than one tenth as great as heretofore. Moreover it is possible by means of
the present invention, to grind the surfaces of the discs, plates or other articles
automatically and with great certainty to the exact curvature desired, and to
dispense with the necessity of skilled workmanship and of feeding the article across
the edge of the grinder.
These results are accomplished in the following way viz. :-
The disc is presented to the grinding wheel, not at right angles to the face
of the wheel, as heretofore, but in a plane substantially parallel to the face of the
wheel.
If exactly parallel the work will be ground flat, but if slightly oblique it will be
concave or convex, the amount of obliquity determining the arc of concavity or
convexity to be given to the disc. If that edge of the disc which overlaps the
wheel is inclined away from the latter, the disc will be ground concave; but if
inclined towards it, the disc will be ground convex, the amount of concavity and
convexity being proportional to the angle of inclination. If parallel it will be
ground straight.
Assuming the grinding to be concave, the corner of the grinder acts first on the
inner edges of the annular disc, and the latter is fed forward (or the wheel may be
advanced) as the grinding proceeds until the grinder has hollowed out the entire
face of the disc. The disc is not displaced laterally with respect to the axis of the
wheel.
By this method of grinding unskilled workmen are enabled to grind discs at an
average of ten or more per hour.
Preferably the grinding is effected by means of a soft cup-shaped or hollow
grinding wheel containing salt or similar soluble material as herein before described.
When flat surfaces are ground on the edge of a wheel in the old way, the plate or
disc must be fed laterally across the grinding edge, there being only a single line of
contact, and at first only a small portion of the surface being ground is in contact
with the wheel, causing excessive grinding action at that part. Another conse-
quence is that the piece being ground is heated and caused to expand unequally at
different parts, more metal being removed at the heated and expanded places, so
that when the piece cools and assumes its normal shape an uneven and untrue
surface is the result. On the other hand when the piece is ground according to the
present invention, that is to say by placing it against and overlapping the face of
the grinder and then revolving it in contact with said face, the necessity for lateral
feed is dispensed with, and every point of the surface of the metal is acted upon by

page_text: the grinding wheel at each revolution of the former, whereby the aimcuities above
referred to are obviated and a surface is ground more nearly true than could be
obtained in any other way. It will be readily understood that the revolution of
the disc while being ground distributes the heat generated by the grinding, over
the entire disc, and the action is at all times uniform, whereas in the old method of
grinding the heat was localized at the part in contact with the wheel, the extent
of contact being at first very small and consequently varying as the disc is fed
across the edge of the wheel.
And in order that this invention shall be fully understood I shall now proceed
more particularly to describe the same and for that purpose shall refer to the
several figures on the annexed sheets of drawings the same letters of reference
indicating corresponding parts in all the figures.
In the said drawings Figure I to XVI illustrate mechanism for grinding irregular
or uneven surfaces according to this invention, and Figures XVII to XXII,
illustrate mechanism designed more particularly for grinding flat, concave aud
convex surfaces according to this invention.
Figure I shews in side view a knife blade after grinding in accordance with this
invention.
Figure II is a longitudinal section on line II and
Figure 111 a trausverse section on line III of Figure I of the said blade.
Figure IV illustrates the mode of grinding the shoulder on the blade as hereto-
fore performed.
Figure V illustrates the improved mode of forming the shoulder wholly by
grinding.
Figure VI is a horizontal section of a machine constructed in accordance with
this invention, the section being taken through the axis of the grinder and the work
holding devices being shewn in plan.
Figure VII is a front elevation partly in vertical section.
Figure VIII is a central vertical longitudinal section, the grinding wheel and its
arbour being shewn in side elevation.
Figure IX is a vertical cross-section on line IX (Figure VI) looking to the
rear.
Figure X is a partial plan view of the work holding devices arranged to grind
the back of the knife.
Figures XI and XII are details in longitudinal vertical section and transverse
section respectively of the work holding slide and accessory parts.
Figure XIII is a detail of the oscillating segment for conveying motion to the
slide.
Figure XIV is a detail in plan of the automatic stop mechanism for arresting the
feed slide at the end of the stroke.
Figures XV and XVI are details illustrating part of the automatic adjusting
mechanism for the grinding wheel.
Referring to Figures I-V, a represents a knife blade ground to proper shape.
From the shoulder a', which should be nearly square, to the dotted line III the
blade is flat, and from that line to the point a² it is curved or tapered as shewn in
Figure 1. If ground straight to the end in the ordinary way the blade will have
the same thickness at the point a as at the other points along the section of
Figure II, and the curved part of the cutting edge would have to be formed by a
separate operation.
The back a³ of the blade is ground flat from the right hand end to the dotted
line III, and from that line is rounded or curved to the point a².
The chamferred portion at presents the same features as the side of the blade,
that is to say it has a square shoulder and is flat to about the dotted line III, and
then curved to the point a³.
In grinding the side of the blade, if the point is first brought in contact with the
wheel, and then fed along till the rear end of the surface to be ground reaches the
wheel, (as is done in grinding table knives, &c.) the effect will be as shewn in

page_text: Figure IV in which represents part of the grinding wheel. In that method the
greater part of the wear occurs at the corner of the wheel which acts first upon
every part of the blade, the wear on the grinding face increasing in degree towards
this corner and gradually rounding it, as indicated in the drawing. Consequently,
except upon the first few articles ground, the required shoulder cannot be cut by the
wheel, rendering another operation necessary.
The improved method is illustrated in Figure V. According to this plan the
blade is first fed directly against the wheel extending across and beyond
the grinding face as shown. The shoulder is thus cut by the sharp corner band
the blade then fed away from this corner (instead of towards it) until the point
of the blade is ground. In practising this method it will be readily seen that the
wear on the face of the wheel diminishes towards the corner 6 by which the
shoulder is cut,
being the opposite corner 62 which sustains the maximum wear;
and that the effect of the abrasion of the wheel in this case is to keep the corner b¹
sharp.
Referring now to the other drawings, the grinding wheel is of the ring form
hereinbefore described, and preferably of the particular composition herein set
forth, and is mounted on a horizontal shaft or arbor B, suitably supported in
hearings, and provided with the usual fast and loose pulleys. The wheel turns in a
trough B adapted to contain water and to supply it by a spout B2 to the interior
of the wheel, and the latter is partly enclosed by a guard or casing B³ all substan-
tially as in machines described in the Specification annexed to Letters Patent
No. 22421 dated 22nd December 1891.
The work holding slide C rests on a dovetailed support C₁ (Figures XI and XII)
and can reciprocate thereon. This support has a tubular portion C which is
pivoted in a socket C³ in the frame (Figure VII). Consequently the slide C, by
the rotary movement of the support C¹, and by its own independent reciprocating
movement, is capable of universal motion in a horizontal plane. It can therefore
(when properly guided) be moved in, or parallel with the plane or rotation of the
emery wheel or grinder, being subsequently moved towards the latter to bring the
blade a against it in order to begin the operation of grinding at the shoulder (this
being the position of the parts as shewn in Figure VI) then moving backwards in
a straight line, grinding the flat portion of the blade, and then in a curved line,
compounded of its own motion and the axial motion of the support C¹, grinding
the curved portion of the blade. The devices for reciprocating the work holding
slide are in some respects such as have heretofore been used. The novel features of
this part of the construction reside mainly in the automatic guiding of the slide in
irregular lines, and in the means for starting and stopping the same.
is
The slide C has on its underside a rack c which engages a pinion c¹ on the end of
an upright shaft c² which has a similar pinion 3 on its lower end. The pinion
engaged and actuated by a segmental arm D (Figures VII and XIII) which is
pivoted at d to the frame and is oscillated by means of a pin d' attached to the
arm D and entering a cam groove in the drum or cam wheel D' (see Figure VIII).
This gives the slide C a reciprocating motion transversely to the axis of the
grinder.
The shaft is made in two parts for convenience in removing the slide and its
support when desired. The upper part is fastened by a pin 10 to a ring 11, and
the lower part is similarly fastened by a pin 12 to a ring 13.
The two rings are
coupled by upright pins 14, 15, which are fast in one of the rings (the lower) and
fit loosely in holes in the upper ring. Thus the upper part of the shaft may be
readily uncoupled from the lower part. This, of course is merely a convenient
arrangement and not an essential feature of the construction.
To grind the side of a blade as in Figure VI the slide C must have a motion
towards the wheel in the direction of the axis thereof. To this end a guide arm E
is detachably secured by screws or otherwise to the slide C. At its free end this
arm has two pins or rollers ee the latter being carried on the end of a spring E¹
which presses it towards the roller e¹. Between these rollers or pins is a guide bar

page_text: or former F which controls the positions of the slide Caxially as it is reciprocated
back and forth. It will be obvious from inspection of the drawings that as the
rollers e'e follow the guide bar F the slide Ċ while moving lengthwise will be
caused to revolve on the axis of the shaft c² as a center when the contour of said
bar deviates from a line parallel with the plane of rotation of the grinder, and by
giving to the guide-bar or former a suitable outline the work-holding slide may be
turned or revolved in either direction, and to any desired extent, within certain
limits. Special importance is not attached to the particular devices described for
guiding the work-holder, as these may obviously be modified or replaced by other
devices capable of performing substantially the same functions. The essential
feature or principle of this part of the invention consists in providing automatic
means for giving the work-holder an irregular movement.
As shewn in Figure VI the guide cam or former F, is secured rigidly to the long
lever F pivoted to the frame at f and capable of horizontal oscillation. The
function of this lever is to swing the work-holder towards the wheel so that the
corner b¹ may strike the blade at the point where the shoulder is to be cut, as
already explained. This notion is communicated to the lever F¹ in the following
way riz. The said lever has on its underside a recess f¹ (Fig. VII) which is
entered by a wrist-pin f' on a disc F2. Disc F is carried by an upright spindle G
suitably supported in bearings in the frame, and having at its lower end an arm G',
which extends horizontally towards the cam wheel D and has a pin g which enters
a second cam groove g¹ in the periphery of said wheel (Figs. VII and VIII).
Through these connections the lever F is at the proper moment turned in the
proper direction to throw the knife blade into contact with the wheel. The shape
of the cam groove d² g¹ will, of course, depend upon the character of the work to
be done. As shewn in Fig. X the lever F and its actuating mechanism are not
always essential. In that figure the grinding of the back of the knife blade is
illustrated. In this instance the guide arm E is provided with a single pin or
roller e entering a cam groove e³ in a stationary guide plate E2. This groove is
straight for a certain distance and then curved, so that the slide C will travel in a
line parallel with the plane of the grinding surface until the curve in the back of
the knife blade is reached and then be deflected so as to keep the curved part of the
blade against the grinding wheel. The cam groove here is the obvious equivalent
of the cam bar in the other figures.
The means for starting and stopping the feed movement will next be described.
Power is transmitted from the shaft 16 having the loose pulley 17, and fast
pulley 18, to the shaft 20 having band pulleys 21 (Figs. VI and IX) the speed of
the latter shaft being much less than that of the former. On the inner end of
shaft 20 is a small pinion 22 (Figs. VI and VII) which engages and drives a large
toothed wheel H which is on the shaft H' carrying the cam wheel D'. Shaft H¹ is
thus driven at a low rate of speed.
The belt which drives the shaft 16 from which the feed-movements are derived
is controlled by a belt shipper K (Figs. VI and XIV) carried by a rod L
extending backwards from the front of the frame and having at its forward end an
elbow or bend L¹ for shifting it by hand as hereinafter explained.
The rod L is surrounded by a spiral compression spring M, which bears at its
forward end against the frame, and tends to push the rod backwards, or in the
direction to throw the belt from the fast pulley 18 to the loose pulley 17.
Consequently, whenever the rod is released it at once arrests the feed movement.
The rod L may be moved in the opposite direction to start the feed by means of a
treadle N, rock-shaft N' and upright arm N2 (Figs. VII and VIII). The upper
end of the arm N* lies between two bosses n' n² on a collar n (Fig. XIV) which is
screwed fast to the rod L. The arm N is also flexible or springy and presses
against the collar n which has a flat surface on the side adjacent to said arm as
seen in Fig. VII. The rod L also carries a finger or detent m screwed fast to the
rod so as to follow it in either a longitudinal or an axial movement. When the belt
is on the loose pulley this detent or finger m bears with slight pressure on the

page_text: rim H of wheel H the pressure being due to the resiliency of the arm N' bearing
as already explained against the collar n which at this time is tilted at a slight
angle to the said arm. To start the feed, the operator puts his foot on trea⋅lle N
swinging arm N forward, moving rod 1 lengthwise in the same direction and
shifting the belt to the fast pulley. This movement of the rod L carries the
finger m past the rim H2 of the wheel H and the pressure of the arm N2 on the
collar n turns or rotates the rod L slightly until the flat face of the said collar is
parallel with the said arm as shewn in Fig. VII. This slight rotary movement of
rod L is just sufficient to carry the finger m inwards so that its free end is caught
and held by the edge of the rim H². Consequently although the operator
immediately removes his foot from the treadle the rod L is retained in this position
against the pressure of its spring M and the work-feed continues in operation.
The rim H2 is provided at one point with a depression or notch (Fig. VII).
When this notch comes opposite to the detent m the latter is no longer held and
the spring M at once acts, pushing the rod L back and shifting the belt on to the
loose pulley. This notch is in such position that the feed is arrested at the moment
when the work-slide C reaches the end of its return movement (to the right
in Fig. VII). Now when the operator inserts a new piece of work into the holder
he puts his foot on the treadle and the shaft H' begins to rotate.
The cam
groove begins to oscillate the arm D and the slide C moves towards the axis of
the wheel bringing the work opposite the grinding face of the latter. The pin d¹
now travels for a while in the straight part of the groove 2 during which time the
groove g' swings the arm G' and lever F as herein before explained bringing the
blade up against the grinding wheel until the shoulder is out. When this movement
is completed the groove swings the arm D in the opposite direction and the slide C
begins to retreat maintaining the blade in contact with the grinder. The movement
is at first in a right line grinding a flat surface on the blade but as the slide nears
the end of its travel it is deflected by the action of the guide-arm E and the
curved part of guide-bar or formner F thus moving in a line which is the resultant
of its rectilinear and rotary movements and grinding the curved part of the blade
terminating at the point. At this moment the reciprocating movement of the
slide C ends and the cam groove g' causes it to turn away from the wheel and on
the completion of this movement the releasing notch comes opposite to the
detent m and the feed is automatically arrested.
In case of any accident necessitating the stoppage of the feed before it completes
its movement this can be effected by slightly depressing the bent end L₁ of rod L
turning the latter far enough to release detent m from engagement with rim H³ and
permitting the spring M to shift the belt from the fast pulley.
The special construction and disposition of parts for effecting the starting and
stopping of the feed movement while advantageous, admit of much modification,
the broad novel features of this part of the invention residing in the starting of
the feed movement by means of a foot treadle and the automatic stoppage thereof
at the completion of each movement.
The mechanism for automatically adjusting the grinding wheel at intervals to
compensate for wear will now be described.
The shaft or arbor B of the wheel is surrounded by a sleeve P (Figs. VI and IX)
having bearings in the frame in which it can move longitudinally without turning.
The said sleeve is screw threaded externally (Fig. VI) for a portion of its length
and engages with an adjusting wheel P whose hub is correspondingly screw
threaded internally and which is held from endwise movement by two collars p p
which form the bearings of the sleeve P. The wheel P' has a threaded rim which
is engaged by a small pinion 9 (shewn in dotted lines in Fig. XV) on a short
shaft q which has bearings in a bracket q² (Fig. IX). This shaft also carries a
ratchet wheel Q with which engages with a pawlr pivoted on a plate R which
swings freely on the shaft q'. The pawlr is held in engagement with the ratchet Q
by a spring (Fig. XV). The plate R receives motion from an upright rod S
which passes through a hole in the boss R¹ of the said plate and is secured by a set

page_text: screw S. The lower end of the rod S is jointed to an arm T projecting from a
rock shaft T (Fig. IX). The forward end of this shaft carries a lug t which lies
in the path of a pin t¹ projecting from the rear of the wheel H (Figs. VIII and IX).
This pin acts upon the lug t once in each rotation of the wheel H depressing it and
giving an upward thrust to the rod S, this motion being transmitted by the pawl r
ratchet and pinion 9 to the adjusting wheel P'. The grinding wheel is thus
intermittently moved a short distance towards the work-holder.
It is obviously desirable that this adjustment should be capable of regulation to
meet varying conditions of work. This may be effected by loosening the set
screw S¹ and moving the rod S downwards to lengthen the stroke of the pawl or
upwards to shorten its stroke.
Many departures may be made from the details of construction herein described
and shewn without departing from the spirit of the invention and some of the
For
elements of the machine may be replaced by devices equivalent in function.
example for the shifting belt and fast and loose pulleys other well known means for
starting and stopping a shaft may be substituted.
Referring now to Figures XVII-XXII the operations followed in grinding
discs, die-blocks plates or other articles to a flat, convex or concave surface are
next hereinafter described.
Fig. XVII is a front elevation of the machine partly in section.
Fig. XVIII a plan view thereof partly in section.
Figs. XIX and XX are enlarged details illustrating the grinding of a concave
and of a convex disc respectively.
Figs. XXI and XXII are respectively an elevation and a horizontal section
shewing a piece being ground to a straight or flat surface.
In the drawing A is a trough adapted to contain water and is supported on a
pedestal A' and partly covered by a hood B. C is a cup-shaped grinding wheel
mounted on a horizontal arbor C₁ having fast and loose pulleys c, c.
The wheel C is covered by the hood B and is also partly protected in
front by a vertical guard plate B'. Water is conducted to the interior of the
wheel by a trough D and is spread by centrifugal force over the grinding surface
of the wheel.
E is a horizontal table, supported by a bolt e which passes up through a sleeve F
resting on the bottom of the trough A. The table E is capable of rotating
horizontally on a vertical axis. An adjustable plate G rests on the table E the
said plate having cross-slots ffl which are intersected by a longitudinal slot el in
the said table. Through the table E and through the points of intersection of the
said slots, pass holding bolts g having nuts g', and the plate G is adjustably
secured to the table E during the operation of grinding by means of the said
bolts and nuts.
The plate G carries a sleeve H which is fast thereon and within the sleeve H is
another sleeve I provided with a feather i which lies in a groove in the outer
sleeve, so that the sleeve I can slide longitudinally but cannot rotate.
The sleeve I constitutes a bearing for a hollow spindle K which carries at its
outer end a driving pulley K' and at its inner end a plate L against which the
discs are held whilst being ground. To prevent lateral displacement of the disc
the plate L has a projecting boss as shewn in Figs. XVIII, XIX and XX which
is adapted to fit in the central opening of the disc M. If the latter is very thin
or has no hole in it the boss is replaced by a projecting ring 1 (Fig. XIX) which
encircles the disc. Whichever of these arrangements be used, it is evident that
the operation of slipping a disc onto the holder or removing it therefrom may be
very quickly performed.
い
The sleeve I is encircled near its outer end by a hand wheel N whose hub n
(Fig. XVIII) is screw-threaded externally and engages threads in the fixed
sleeve H. By rotating the wheel N, the sleeve I and with it the work holder may
be moved lengthwise towards and from the grinding wheel C.

page_text: It is obvious that devices of various kinds may be used to effect these adjust-
ments. The adjustments hereinbefore described in connection with the grinding
wheels may also be employed in this machine.
The work-holder may be adjusted towards and from the axis of the grinder by
means of the slot e¹ and may be turned more or less obliquely to the face of the
grinder by means of the cross-slots ff'.
The outer corner p of the face of the grinder C intersects the central opening m
of the disc or cutter M which is being ground. Consequently the grinding takes
place on both sides of this central opening.
If the side m² of the disc which is nearest to the axis of the grinder be inclined
away from the latter, as shewn in Figs. XVIII and XIX a concave face will be
ground upon the disc. The grinding will begin at the edge of the central
opening m which at first is the only part that touches the face of the grinder and
will continue until the entire face of the disc is hollowed out. The degree of
concavity will depend upon the angle of inclination of the disc M from the face
of the grinder.
When the work is to be ground concave the bearing plate L of the work-holder
is made convex to fit the shape of the finished disc so as to furnish a perfect support
therefor. The disc is placed upon its holder and advanced by the wheel N into
contact with the grinder and the disc and grinder are then rotated, preferably in
opposite directions. Since the disc has a flat face in contact with the couvex
bearing plate L the former would have a tendency to spring, as the grinding
proceeds farther and farther from the centre of the disc. To avoid this the disc
after being ground on one face is reversed and ground to the same extent on the
other until the grinding is complete. Thus the disc is always supported by the
bearing plate opposite or nearly opposite to the line of action of the grinder.
If the side m¹ of the disc nearest to the axis of the grinder be inclined towards
the latter (as represented in Fig. XX) the result will be a convex surface the
grinding beginning at the outer edge.
In this case the bearing plate L should have a concave surface. The method of
reversing the disc at intervals is employed for the same reason as in the grinding
of concave discs.
The disc is fed in the direction of its axis of rotation as the grinding proceeds
or the grinding wheel may be fed forwards so as to produce the same effect.
When the work is to be ground flat it is presented parallel to the face of the
grinder. This operation is indicated in Figs. XXI and XXII. The worm M
which in this case is a rectangular plate, is held between the chuck-jaws Q carried
by the spindle K by which the work-holder is rotated as hereinbefore described.
On referring
The chuck-jaws are adjusted by screws g in a well known manner.
to these figures it will be seen that at each revolution of the worm plate M² every
point of its surface will be acted upon by the grinder C and that the pressure
(which is the same whether a small or large surface of the work bears against the
grinder) and also the heat generated by friction are evenly distributed.
The improved grinding wheel or grinder containing soluble or absorbent
material may be used in various kinds of grinding machines other than those
herein before described and the devices for grinding irregular, or curved, or flat
surfaces may be utilized with good results in connection with wheels of ordinary
composition; but in all cases the best results are obtained by means of grinding
wheels of the particular composition described that is to say wheels which contain
salt or equivalent substance.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is
1. A grinder or grinding wheel of cup-shape or other suitable form, composed
of an abrading material a binding agent such as shellac, and a material which is

page_text: readily absorbent of or soluble in water such for example as common salt
substantially as hereinbefore described.
2. In a machine for grinding articles having an irregular surface, the com-
bination with a grinding wheel of a work-holder capable of universal motion in
one plane and an irregular guide for controlling the movements of said work-
holder substantially as hereinbefore described with reference to the accompanying
drawings.
3. In a machine for grinding articles having an irregular surface the com-
bination with a grinding wheel, of a work-holding slide supported so as to be
capable of universal motion in one plane, means for reciprocating the said slide
in line with the grinding surface of the said wheel and a guide of irregular
outline for deflecting the said slide from the line of its reciprocating move-
ment substantially as hereinbefore described with reference to the accompanying
drawings.
4. The combination with the grinding wheel, of a work-holder a swivelled
support therefor, means for reciprocating the slide on its support, a guide for
changing the positions of the said support and slide while the latter is recipro-
cating on the former, a movable support or lever carrying the said guide and means
for moving the said support towards and from the grinding surface of the said
wheel substantially as hereinbefore described with reference to the accompanying
drawings.
5. The herein described method of and means for grinding articles, such as knife-
blades, having a shoulder thereon by presenting the article against the grinding
surface in such position that the shoulder will be first ground by the corner of the
wheel, and then feeding the article by means of suitable automatic feeding devices,
across the grinding surface away from such corner substantially as hereinbefore_
described with reference to the accompanying drawings.
6. In a grinding machine, the combination with the grinder and automatic feed-
mechanism, of a starting and stopping device, such as a belt-shipper, an actuating
rod therefor, a treadle for shifting the said rod in the direction to start the feed, a
detent for holding the rod in this position and means for releasing the detent_auto-
matically at a predetermined moment substantially as hereinbefore described with
reference to the accompanying drawings.
7. In a grinding machine the combination with work-holding devices, of a rotary
grinder, an adjusting wheel for moving the grinder in the direction of the work-
holder and means for intermittently actuating the said wheel substantially as
herein before described with reference to the accompanying drawings.
8. In a grinding machine, the combination with the work-holder and its actuating
devices, of a rotary grinder intermittently operating mechanism for moving said
grinder towards said work-holder to compensate for wear and means for regulating
the amount of such motion substantially as herein before described with reference
to the accompanying drawings.
9. The described method of grinding the face of a disc or plate by presenting
it in contact with the circular face of a grinder in such manner that the wheel
overlaps and embraces about half the work, the rest of the surface of the latter
projecting beyond the outline of the wheel, and rotating the work so that at each
revolution every point of its surface passes across the grinding face of the wheel
the relative positions of the axis of the work and of the grinder being maintained
throughout the operation substantially as herein before described with reference to
the accompanying drawings.
10. The method of grinding the face of a metal disc to a curved surface, by
presenting the disc to the face of a grinding wheel so that about half the surface
of the disc overlaps the face of the wheel said disc being inclined at a slight angle
with said face, rotating the disc and feeding it in the line of its axis of rotation as
the grinding proceeds, substantially as hereinbefore described with reference to the
accompanying drawings.

page_text: 11. In a machine for grinding metal discs to a concave, straight or convex
surface the combination with the grinding wheel of a work-holder adapted to hold
the disc against the face of the grinder and mounted on a support which is
adjustable to present the face of the work-holder at different angles or parallel to
the face of said wheel, means for rotating said work-holder on its axis, and means
for moving it in line of the axis while the grinding proceeds, substantially as
herein before described with reference to the accompanying drawings.
12. The combination with the grinding wheel, of a table for supporting
the work-holding devices, a plate adjustable axially and also adjustable trans-
versely with respect to the face of the grinding wheel, a rotatable bearing-plate
adjustable in its support in the line of its axis, and a holding projection on the
face of said plate substantially as hereinbefore described with reference to the
accompanying drawings.
13. The arrangements and combinations of parts constituting the improvements
in apparatus for grinding iron and steel and other articles substantially as herein-
before described and illustrated in the accompanying drawings.
ית.'
cambion 1002
J. H. JOHNSON & Co.,
Agents.