Year: 1887

page_text: Date of Application, 22nd Mar., 1887.
Specification Accepted, 29th Apr., 1887.
I, HENRY HARRIS LAKE, of the firm of Haseltine, Lake & Co. Patent Agents,
Southampton Buildings, in the County of Middlesex, 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 :-
My invention relates to improvements in apparatus for grinding the knives of
mowing and reaping machines.
My said improvements have been devised with special reference to their use in
connection with that class of machines which were disclosed in the specification of
Letters Patent dated May 25th, 1886 No. 7030 although some of the features now
disclosed have more or less value, when applied to other types of mower knife
grinders.
One of the most important features of my present invention is believed to be
radically new, and of equal value in any mower knife grinders, wherein spring pressure
is relied upon for maintaining contact between the knife and grinding wheel during
the actual grinding operation, and also wherein either the wheel or the knife clamp
are reciprocated for progressively grinding the edge of a knife section from the bottom
to its tip. In all prior machines the spring which controls the knife clamp exerts
greater force, and causes heavier contact of the knife with the grinding wheel, while
grinding the bottom of each knife edge, than while grinding the tip or upper or outer
portion of the same edge, because of the fact that although the spring is compressed
by the rearward deflection of the knife clamp, as when grinding at the tip of a knife
section, the effective force of the spring is greater while grinding at the bottom of
the V which is nearer the fulcrum or pivot of the knife clamp or its frame, than the
outer end or tip of the knife edge. The application of the greatest spring pressure
while the grinding wheel is operating on the bottom of the V of a knife, as heretofore,

page_text: is obviously bad in principle inasmuch as the outer portions of each edge do more
work and are consequently inore liable to wear, than the inner portions, and hence the
latter will usually need less grinding, and instead of being ground under the greatest
available pressure, said inner portions should be ground under a pressure at least no
greater than when the outer portions are being ground, or in other words it is highly
advantageous if the spring pressure be practically equalized so as to secure a uniform
contact pressure while grinding all portions of an edge, but I deem it best to have the
pressure somewhat greater while grinding near the tip of a knife section than while
grinding at the bottom of the V, and I have therefore for the first time so organized
a knife clamp controlling spring, with the grinding wheel frame, and the clamp frame,
that the spring will exert its minimum force, while the grinding wheel is in contact
with the bottom of a knife edge, and then progressively increase its force as the point
of contact is gradually moved toward the tip of the knife edge or section. Although
I have provided for this progressively increased pressure, while grinding outward, and
a gradually decreased pressure while grinding inward, on a knife edge, my spring can
be so adjusted as to enable the pressure to vary so little as to make it practically
uniform. Another feature now devised by me is specially applicable to such machines
as were described in the aforesaid specification and in which the grinding wheel frame,
and the knife clamp frame are swivelled together and movable in the arc of a circle
centreing within the grinding wheel. In said machine stops are employed for limiting
the swivelling movement, and as heretofore organized by me, said stops were absolute
in their operation, and fixed in their positions, which rendered the machines thoroughly
satisfactory when used for grinding new knives, or even old knives, which had only
been ground in my machines, but a knife having more or less irregularly ground
knife sections, as a result of their having been previously ground upon an ordinary
grindstone, or by means of other types of grinding machines, requires that there
should be a capacity for a special adaptation to each knife section in order to widen
the
range of usefulness of said machine.
In this connection another feature of my invention consists in providing swivelling
stops which are adjustable, so that they may be moved toward the right hand or
toward the left, and be then firmly fixed in position, thus while restricting the extent
of the swivelling movement as between the knife clamp frame and the wheel frame,
the same as in my prior machines. I now further provide for a variable location of
said stops to enable the swivelling movement between the knife clamp frame and the
wheel frame to be correspondingly varied.
Another feature of my present invention is mainly restricted in value to use in that
form of machine described in my said specification in which the grinding wheel is
mounted at the end of an arm pivotted upon the wheel frame so as to allow the wheel
to be vertically reciprocated by the hand of the operator applied to a handle at the
opposite end of said arm.
In my said prior machine the wheel driving crank, and the driving gear coupled to
said crank, were located at and upon the pivot by which the wheel arm and wheel
frame were connected, and while that arrangement is highly effective I have found
that some persons while operating the crank with the right hand and controlling the
wheel with the left hand, experience more or less difficulty in preventing the power
applied through the crank from adversely affecting the desired control of the grinding
wheel, and I have greatly remedied this by providing an independent base for the crank
and its gear, and meshing the latter with an intermediate gear, which is mounted
upon the wheel arm pivot, and as a further result of this change and its accompaniments
the machine is rendered more compact, and much lighter in weight than my prior
machines of this general form.
With a view to further lessening the weight of the machine as well as its cost, I
now employ a knife clamp embodying certain novel features, and of simpler construction
than those used in my prior machines, which with the other changes now made enable
me to produce a thoroughly effective machine weighing only about two thirds as much
as machines of the same general class as heretofore produced by me.
In my prior machines, a chambered grinding wheel is employed, for the reception

page_text: of water, and employ such wheels in my present machines, but I have now so
improved them that water can be more conveniently introduced and retained therein.
In my prior wheels, a feed duct and a plug were employed, but I have now provided
a duct which need never be closed, and which can be provided with a mouth by which
water can be readily supplied to the wheel while it is in its working position, and
without the aid of a funnel or other special contrivance.
To more particularly describe my invention I will refer to the accompanying
drawings, in which
Figure 1 is a side view of a simple form of my machine embodying all of my
present improvements.
Figure 2 is a top view of the same.
Figure 3 is a side view opposite to that in figure 1.
Figures 4 and 5 are respectively side and top views of such portions of this machine
as relate to varying the angular adjustment of the grinding wheel and knife clamp.
Figures 6 and 7 in two views illustrate a plate metal spring for controlling the
knife clamp.
Figure 8 illustrates a rubber spring for controlling the knife clamp.
Figures 9 and 10, in two sectional views illustrate the chambered grinding wheel
provided with my novel water feeding duct.
Figures 11 and 12, in side and sectional views illustrate the grinding wheel
provided with my feeding duct in another form.
Figure 13 is a front view of a knife clamp detached, or portion of a mower knife
being therein indicated in dotted lines.
Figure 14, is an end view of said clamp, and also of the lever by which it is in part
controlled in its relations to the grinding wheel.
Figures 15 and 16, in front and top views illustrate one pair of knife clamping
jaws in a modified form.
Figure 17 in side view illustrates a base clamp, a knife clamp, a portion of the
wheel frame, and the adjustable stop devices in a modified form.
Figure 18 is a top view of the base clamp plate and adjustable stop plate of figure 17,
with the knife clamp removed, but having a portion of the wheel frame shown in
dotted lines.
Figure 19 in end and top views illustrates said clamp plate, detached.
Figure 20 in side and top views illustrates the plate which carries the adjustable
stops, detached from the clamp plate.
Figure 21 is a side view of a complex form of my machine capable of various modes
of operation, and illustrating the main features of my present invention as applied
thereto.
Figure 22 is a side view of a vertically reciprocating knife clamp, having a bent
spring arranged to progressively increase its force during the downward movement
of the clamp.
The grinding wheel A as in my prior machine is chambered for the reception of
water, which is delivered through the grinding face, as a result of the rotation of the
wheel. In lieu of the plugged aperture or feed hole heretofore used by me, I now
employ a feeding duct which requires no closing. This duct can be somewhat varied
n its form, but it must have an entrance or mouth to allow water to flow downward
nd inward, and an exit within the wheel at such a point with relation to the mouth
hat water cannot flow outwardly from the chamber either when the grinding wheel
s at rest or in motion. As shown in Figures 9 and 10, the feeding duct is in the
orm of a bent tube a inserted tightly through a hole in one of the wheel flanges, and
xtended radially a little beyond the axis of the wheel. In Figures 11 and 12, the
uct a is within exterior and interior webs cast integrally with one of the wheel
anges. Either form enables water to be supplied to the chamber through the open
outh a², which of course could be plugged if any one desired so to do, but it will
bviously be wholly unnecessary because in whatever position the machine or the
rinding wheel may be, water cannot flow outwardly unless it he greatly in excess of
desirable quantity. When the wheel is in motion the entire liquid contents of the

page_text: chamber will of course be annularly distributed therein, and evenly, and hence there
will be no tendency for the water to pass entirely through a duct which occupies in the
wheel a line more or less radial. With a considerable body of water within the wheel,
it is sometimes delivered too freely through the grinding face, and to prevent this I
use a water guard a³, composed of an annular band or strip of any material not freely
pervious to water, and while heavy cloth or felt night serve a good purpose I prefer
to use thin sheet metal corrugated as shown and laterally so occupying the chamber
as to not wholly prevent water from passing toward the grinding face of the wheel.
This water guard could, however, be so tightly clamped between the wheel flanges, as
to prevent water from passing at its edges, but in that case a few small perforations
should be provided. A cheap and fairly effective water guard may be provided in the
form of an interior impervious coating to portions of the annular surface of the
grinding wheel, thus lessening the area of exposure to penetration.
Referring specially to Figures 1 to 5, I will describe the wheel frame B, which
differs in some more or less important features from that of any of my prior machines,
but most of said variations are incident to the presence of the more important features
of my invention. As in my prior machine said wheel frame is composed of a bracket
swivelled upon a bed plate, and a wheel arm 33' pivotted upon said bracket as at bas
in my prior machines of the general form. In said prior machines the crank and
its shaft were mounted upon the wheel arm B¹, but now said crank and shaft have
bearings in a rearwardly projecting hanger integral with said bracket below the
wheel arm. The chain of gearing from the crank shaft to the grinding wheel
is substantially as in my prior machine, but the outer bearings for the wheel shaft and
the shaft of the adjacent gear are slightly differently formed being now on a hanger
extended downward from the wheel guard and integral with the arm B' instead of
being extended upward, as in said prior machines.
The base clamp C by which the machine may be securely mounted upon the wheel
of a mowing machine as for use, differs from those previously used by me, in that
instead of four but three jaws are now used, two at one side as before, and one
centrally opposite as at c, on a single bolt e' provided with the thumb nut e². I find
that the one bolt and one jaw amply serves the purpose, thus lessening the weight and
the cost of that portion of the machine.
The knife clamp frame D is pivotted on a horizontal bolt at d to the base plate of the
machine in my prior machines, but it is now provided with a pair of arms slightly
above the plane occupied by the pivot d and projecting toward but at both sides and
beneath the grinding wheel, as clearly indicated in figures 1 and 2. On the base plate,
below the wheel, there is a bow shaped lever pivotted at to the base plate, and at
its two ends bearing downward upon the coincident ends of the arms e of the clamp
frame. At the bow end of the lever there is a hook 3 by which one end of
contractile spiral spring g is attached for flexibly coupling said lever with the wheel
arm B', said spring at its upper end being connected to a screw threaded rod or link g'
which extends through a hole in said wheel arm and is provided with a thumb nut g²
bearing on said arin by means of which said spring may be adjusted to any
desired tension, and to correspondingly vary the force with which the knife
clamp is normally forced toward the grinding face of the wheel. The point of
connection between said spring and its link and the wheel arm B is located
between the pivotal point b and the grinding wheel, and therefore as said wheel is
raised by depressing the opposite end of said arm by means of its handle h, the
tension on said spring is gradually increased, so that on commencing to grind a
mower knife at the bottom of a V, the spring will exercise its normal or least pressure,
but as the wheel is raised for grinding upwardly toward the outer ends of the knife
sections the tension of said spring is gradually increased, until its extreme pressure is
developed while grinding at the outer ends or tips of the edges. The rear end of the
bow lever at its underside, abuts upon a projecting portion of the bracket B
thus enabling the latter at to serve as a stop, by means of which the knife
clamp frame is confined against undue movement, rearward or away from the
grinding wheel.

page_text: The bracket arm of the wheel frame, as in my prior machines, has a forwardly
projecting stud below the wheel serving as a stop by means of which, and two
adjacent abutments, the extent of the lateral swinging movement is restricted, and in
said prior machines said abutments were fixed portions of the machine, but I have
now devised adjustable stops by means of which the angular relations of the grinding
face, and a knife edge can be varied to provide for grinding knives which have not
been previously ground with desirable uniformity, as shown in figures 4 and 5, said
stop abutments, are vertical studs on a flat plate K pivotted at one side near one
end as at K to the base plate, and at the other end provided with a curved slot K³
occupied by a vertical screw post K3 projecting upwardly from the base plate, and
provided with a washer and a thumb nut K, thus enabling said stops or abutments
to be swung slightly to either side of their normal position, and permitting all
variations in the angular relations of the knife clamp and grinding face, which could
be desirable for operating upon mower knives which have been imperfectly or
irregularly ground, prior to the use of my machines thereon. It will be obvious that
it is immaterial in what particular manner these stops or abutments 7, 7, are
rendered adjustable, as will be hereinafter made apparent in connection with other
forms of my machine.
The vertical pivot or bolt at E by which the wheel frame and knife clamp frame are
swivelled with relation to each other is as in certain of my prior machines, and the
base plate E is changed in form only so far as to harmonize with the several
variations in other portions of the machine. It must not, however, be understood
that with my present features of invention the pivot or holt E, is of necessity the only
direct means of connection between the wheel frame and the base plate, or between
the wheel frame and the knife clamp frame, as will hereinafter be fully shown in con-
nection with one form of my machine in which the plate which carries the adjustable
stop abutments, serves also as an intermediate connecting link between the wheel
frame and the base plate.
The knife clamp F shown in Figures 1, 2, 3 13 and 14 differs in many respects
from that shown in Figure 21, the latter being substantially as shown in my said.
Letters Patent. My present clamp has a knife seat at on a horizontal bar l',
which is a portion of the clamp frame D, and at the ends of said bar there are
stationary jaws 1, 1, and for each of these there is a loose jaw m, m', having
a bearing point below said bar at m², for contact with a corresponding portion
of the coincident stationary jaw, and each pair of jaws has a threaded bolt and a
thumb nut. The clamping face of each pair of jaws is at 2 between which a knife
section is clamped above the knife bar, as clearly indicated in Figure 13. At a
nearly central point on said knife seat there is a vertical bolt o, having a head
which will just overlie the edge of a knife bar, when a knife is in the clamp as
for grinding. As in my prior machines this bolt serves as a gauge for locating the
the dividing line between two knife sections, although in this case it is one edge
of the head that serves as a gauge point, as indicated, instead of the centre, as in my
prior machines, and so also does this bolt by the contact of its head with the outer
edge of a knife bar contribute to convenience in adjusting a knife in the clamp.
For conveniently throwing the clamp rearward, one of the loose jaws m is provided
with a thumb piece ³. In using this clamp it will be seen that the bolt o, serves
to prevent a mower knife n³ from tilting endwise and edgwise, and hence one pair of
these clamping jaws can be set so as to confine but not tightly engage with a knife
section, and not require any manipulation of its clamping bolt, during the grinding
of all but one section of an entire mower knife, the other pair of jaws doing nearly all
the actual clamping duty.
For better enabling the clamp to thoroughly control a heavy knife while grinding
an end section, I prefer to construct the loose jaw m, as illustrated in Figures 15 and 16,
wherein said jaw is shown as having the thumb piece n³ and also a laterally extending
arm m³, which enables this jaw to maintain its control over a knife, even when
no knife section is interposed and clamped between the main faces of the jaws,

page_text: it being obvious that the vertical holt o, serves as a clamping face for the rear side
of a knife, and that it co-operates with the arm m' when the latter is forced against
the opposite side of a knife.
Referring now to the novel combination which includes the spring g, as shown
in Figures 1, 2 and 3, it is not to be understood that said spring must be of the
contractile variety, because an expansive spring may as well be employed, as
illustrated in Figure 8, wherein the lever has a tail piece, and a vertical strap f³;
within which is an expansive rubber spring y, through which the link or rod g
passes, the latter having a nut or head at its lower end, and a washer intervening
between said nut, and the lower end of the spring. In lieu of springs of either
of these varieties, a plate spring may be employed, as illustrated in Figures 6 and 7,
wherein the bow shaped lever is composed of three paris. The pivoted portions/
are rigid, but the rear portion is bow shaped, and has a central integral tongue
piece, all composed of spring steel plate, well proportioned for the duty to be
performed, the tongue piece being coupled to the link g' as before described.
In Figures 17 to 20 inclusive I have illustrated portions of one form of my machine
in which the wheel frame bracket B, is as before described, but the base clamp
In this
plate is not directly swiveled to said bracket by the pivot or bolt E.
instance the plate k is pivoted to the base plate E by means of the pivot bolt at k³,
and said plate has at its opposite side a bearing or sleeve, for the reception of the
pivot bolt E. The knife clamp frame is pivoted upon the base plate as in the other
forms of machine, and therefore the general pivotal relations of the grinding wheel
and the knife clamp are as before described, although the plate & serves not only
as a carrier for the stop abutments 2, but also as an intermediate connecting link
between the grinding wheel frame, and the base plate on which the knife clamp
is mounted. This plate & like the similar plate before described has a curved slot k²,
occupied by the screw post 3 having a washer and thumb nut ki, all as previously
described for enabling the adjustment of the stops i¹ and confining them in position.
The spring is here shown in dotted lines, with its lower end connected to
the lever, and the latter instead of being bow shaped has but one curved arm, and
its end engages at but one point with the knife clamp frame D, as at
of at two points as in the instances previously described.
instead
It is now to he understood that this feature of my invention by which progressively
increased spring force is applied to the knife clamp during the grinding contact of the
wheel and knife, starting from the bottom of a V and grinding thence to the tip
of an edge, is not restricted to those forms of my machine in which the grinding
wheel is vertically reciprocated, as it will now be made obvious that similar results
will accrue if the spring be properly applied to a knife clamp and frame which
can be vertically reciprocated, while the wheel is rotated on a non reciprocating arm.
In the complex form of machine shown in Figure 21, the knife clamp is pivoted
to the clamp frame D upon a supplemental frame at d, so that the clamp can be
vertically reciprocated by means of the hand lever p, as shown and described in my
aforesaid English Letters Patent, and as in said prior machine, a spring p, performs
the lifting movement of the clamp frame after it has been depressed by the hand lever.
A knife clamp spring was used in said prior machine, but it was seated at one end
upon a cross bar between the arms by which the knife clamp was pivotally coupled
to the knife clamp frame, and said spring was slightly inclined forwardly to its point
of contact with the knife clamp. In my improved machine the spring has its
rear end abutted against the side of a slotted standard g, and it encircles a rod g
(provided with an adjusting nut 917) so that as the knife clamp is depressed, as
for grinding a knife edge from the bottom of a V outwardly, said spring is
progressively compressed and caused to exert a gradually increased pressure of a
knife in the clamp, upon the grinding face of the wheel, and in a manner as closely
approximating, to the operation of the spring g, before described, as I believe
to be possible, when said spring is not directly controlled and graduated by the
movements of the wheel arm in the simpler forins of machine. In said Figure 21

page_text: the form of knife clamp shown is the same as that disclosed in my said Letters Patent,
but the forms herein disclosed can be used in this complex form of machine,
as is illustrated in Figure 22, wherein the spring 7, 6, is of the simple bent variety,
and composed of spring plate metal, secured at one end by means of a slot therein,
and an adjusting clamp screw ' to the standard gf which as before described projects
upwardly from the base portion of a knife clamp frame, and at its other end it abuts
against the rear of the knife clamp in a suitable seat, so that as the clamp is
depressed, the force of the spring is progressively increased in the direction of
the grinding wheel, and progressively lessened as the clamp rises, thus affording
the same results as with the springs of the spiral form.
It will be observed that in the form of machine shown in Figure 1, the knife
clamp spring is coupled to the wheel arm between its pivot, b, and the wheel,
and also that it has been shown that said location of the coupling point will admit
of the use of either contractile or expansive springs. It is now to be understood
that said coupling point can be located between the wheel arm pivot and the outer
end or handle of said arm, without materially impairing the results.
In this complex
form of machine, Figure 21, the knife clamp can be locked against vertical
reciprocation, and the wheel arm then unlocked so that the grinding wheel can
he vertically reciprocated. It will be readily obvious that in the simple form
of machine shown in Figure 1, the how shaped lever is constructed separately
from the knife clamp arms e simply because the force of the spring is increased
by the upward movement of that portion of the wheel arm to which it is coupled
and hence if said spring be coupled to and controlled by a portion of the wheel
arm which moves downward from its normal position said arms e, may be extended
below and beyond the pivot of the wheel arm, as shown in Figure 21. With
the clamp arms e thus extended, of course the pressure must be exerted downwardly,
and hence the spring 9, abuts at its lower end upon said clamp arms e (the two
being coupled at their rear ends in bow form) and its upper end abuts against
the adjusting nut on the rod go, which at its upper end abuts against a seat
on the underside of the wheel arm, and at its lower end passes freely through a hole
in said clamp arms e. This arrangement of the pressure graduating spring, so
far as its rod and adjusting nut goes, is the same as in the case of the spring 3
before described. It will be readily obvious that in operating a complex machine
like that shown in Figure 21, both clamp springs ; and, could not be used
at the same time, and hence either can be readily displaced or rendered inoperative,
but a machine thus organised being capable of use under all possibly desired
conditions cannot fail to meet the varied preferences or requirements of its user.
It will also be readily seen that however the clamp controlling spring may be
operatively coupled to the knife clamp by way of the wheel arm, or however varied
the spring may be in form, that it will operate in substantially the same way to press
the knife clamp toward the grinding wheel with a gradually increased force in
grinding from the bottom of a V to the tip of an edge, as a result of that reciprocatory
movement, by which the entire knife edge is progressively subjected to contact with
the grinding surface of the wheel; and it will also be as readily seen that when
said clamp controlling springs are not controlled by the pivoted wheel arm (as with
the springs 3, and g, Figures 21 and 22) they are also graduated in force as
the result of that same reciprocatory movement, effected by the hand lever P,
which is pivoted upon the wheel arm bracket, and is vibrated vertically like the wheel
arm in the other forms of machine, thus clearly indicating the fact that the wheel
arm B, when vibrated to progressively vary the force of the clamp controlling
spring, is no more than a hand lever operatively coupled to said spring, and in this
particular combination it is therefore the equivalent of the hand lever p.
If the spiral springs be composed of steel it is generally desirable to loosely house
them for protection against undue corrosion, and to accomplish this a cup sleeve ";
as shown in Figure 21 on the spring gs can be employed with good results on any of
the spiral springs.

page_text: This complex form of machine can obviously be provided with adjustable stops or
abutments mounted on a plate, as in the simpler forms of my machine, but instead of
the swinging plate I have here shown simple stop screws the inner ends of which
serve as adjustable stops or stop abutments, with which the wheel frame stop i, can
be made to variably engage, and thus enable the knife clamp and wheel to befadjusted
for grinding irregularly ground knives, although this form of adjustable stops is not
decmed by me so convenient and desirable as those previously described.
Having now particularly described and ascertained the nature of my said Invention,
and in what manner the same is to be performed as communicated to me by my
foreign correspondent I declare that what I claim is :
1st. In a machine for grinding mowing and reaping machine knives, the combi-
nation substantially as hereinbefore described, of a knife clamp, a grinding wheel,
means for reciprocating either of them for presenting to the grinding surface a knife
edge progressively from the bottom of a V to the tip of an edge, and a clamp
controlling spring which exerts its minimum force during the presentation by the
clamp of the inner end of a knife edge to the grinding surface, and a greater force
when presenting the outer end or tip of a knife edge to said, surface, and is coupled
to the reciprocating mechanism and graduated in its force thereby, substantially as
described, whereby the pressure of a knife held by said clamp is increased progressively
against the grinding surface while grinding from the bottom of a V to the tip of a
knife edge.
2nd. In a machine for grinding mowing and reaping machine knives, the combi-
nation substantially as hereinbefore described, of a knife clamp, a grinding wheel
mounted upon a reciprocating arm or lever, a clamp controlling spring coupled to
said wheel arm, and varied in its force, while pressing a knife against the grinding
surface as a result of the various positions assumed by said wheel arm during its
reciprocatory movement.
3rd. In a mower and reaper knife grinding machine, the combination substantially
as hereinbefore described, of a grinding wheel, mounted at one end of a pivoted arm,
a knife clamp frame pivoted to swing toward and from the grinding face of said
wheel, arms at the foot of said frame, a pivoted lever, bearing downward upon said
arms, and a clamp controlling spring, coupled to the opposite end of said lever and
also to said wheel arm between its pivot and the wheel, whereby as the result of
vertically moving said wheel the pressure of said spring applied at the rear of the
clamp frame is progressively increased.
4th. In a mower and reaper knife grinding machine, the combination substantially
as hereinbefore described, of the grinding wheel and the knife clamp pivoted with
relation to each other substantially as described, for enabling the presentation of a
knife held by said clamp to either of the edges of the face of the grinding wheel, and
adjustable stops for variably limiting the pivotal movements of said wheel and clamp,
and thereby correspondingly varying their angular relations for operating upon the
sections of a mower knife which has been irregularly ground.
5th. In a mower and reaper knife grinder, the knife clamp embodying the combi-
nation, substantially as described, of the horizontal bar provided with legs pivoted at
their lower ends, and having an upper surface affording a longitudinal seat for the
rear edge of a knife bar, and having a centrally located bolt affording a shoulder for
engaging with the outer edge of a knife bar, and the two pairs of independent vertical
clamping jaws located at opposite sides of said bolt, whereby the central portion of a
mower knife may be securely confined by the use of either or both of said pairs of
jaws, and also whereby either of the pairs of jaws and said bolt shoulder can be relied
upon for securely holding either end of a knife while grinding the end sections thereof.
6th. The combination substantially as hereinbefore described of the grinding wheel,
the knife clamp, and its frame, the latter being pivoted at its lower end to a base
plate, a horizontal bar on said frame serving as a seat for the rear edge of a mower
knife bar, a rigid clamping jaw at each end of said bar, a pair of movable jaws each

page_text: provided with a separate clamping bolt, forwardly projecting arms, at the base of said
clamp frame, and a spring for forcing said arms downward, and thereby forcing the
knife clamp toward the grinding face of the wheel.
7th. In mower and reaper knife grinder, the combination with a grinding wheel,
internally chambered for the reception of water of a radial water duct having an
external feeding aperture, and an internal exit located within the wheel, substantially
as described whereby water can be readily supplied to the chamber, and then securely
retained therein without closing said duct, regardless of variations in the position of
said wheel, and whether the same be in or out of use.
Dated th: 001
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicants.