Improvements in Clippers for Shearing Sheep and like Uses.
Year: 1899

page_text: Date of Application, 13th July, 1899
Complete Specification Left, 10th Apr., 1900-Accepted, 30th June, 1900
PROVISIONAL SPECIFICATION.
Improvements in Clippers for Shearing Sheep and like Uses.
I, JOHN KERWIN STEWART, of No. 158, Huron Street, in the City of Chicago,
County of Cook, State of Illinois, United States of America, Mechanical Engineer,
do hereby declare the nature of this invention to be as follows:-
My present invention consists of certain detail improvements in devices for
pivotting and applying pressure to the cutter-actuating lever-arm and pressure
bar of a shearing tool for hair-cutting, sheep-shearing and the like; the purpose
of said device being to adapt the oscillating cutter to accommodate itself more
perfectly to the fixed cutter or comb under the different tensions which may be
employed, and to avoid the inequality of pressure which may otherwise be exerted
upon the oscillating cutter at different parts of its path, rendering the tool, in this
respect, less sensitive to slight derangements of position of the parts, such as is
liable to be caused in the adjustments incident to use, cleaning etc.
My improved shearer comprises a shank or handle having at its forward end,
and integral with it, an expanded portion which constitutes the body of the
housing for the operating parts; the fixed cutter or comb which is rigid with the
housing at the forward and lower side; a cap or upper plate for the housing: a
steel bushing which is driven in the sleeve or handle of the housing and which
affords bearing for the operating shaft which extends through the sleeve and has,
at its forward end, the crank for the oscillating cutter.
The oscillating motion is communicated to the cutter from the crank through
the medium of the lever, which is pivoted in such manner as to have swivel
movement, and also movement of oscillation both horizontally and vertically about
its pivotal attachment, which is obtained. upon the end of the steel-bushing
referred to, said bushing being protruded from the sleeve into the housing for
that purpose. The means which I prefer for this pivotal attachment of the lever
comprise a loose ring or sleeve, which is seated on the reduced inner end of the
bushing and retained by a collar: the cutter-actuating lever being forked to
stride the end of the bushing and the ring, and pivoted to the latter at the ends
of both fork-arms, one above and the other below the ring and bushing, the
pivotal attachment being of such nature as to permit a slight vertical oscillation,
in addition to the horizontal oscillation about the vertical pivot, while a swivelling
movement, it will be observed, is obtained by virtue of the ring to which it is
thus pivoted. The vertical oscillation may be obtained by making the pivotal
joint comprise a slightly, and almost imperceptibly, elongated slot for the pivot
pin but for more perfect accommodation in this respect I may construct the
jcint by forming on the end of the steel bushing, a spherical swell or knob-like
seat, and making the ring which is swivelled on the bushing to fit this seat,-
forming it in two parts so that it may be assembled about the latter, thus
producing a ball joint with sufficient range of oscillation in a vertical plane, the
forked lever being pivoted to the ring as in the other construction. For the
purpose of communicating motion to the lever, the crank has a spherical anti-
friction roller, which operates in a vertical cylindrical track-way formed in the-

page_text: lever arm forward of the pivoted fork ends. The lever engages the oscillating
cutter by fingers at the forward end, taking into suitable apertures in the cutter,
and pressure is transmitted through the lever by means of the secondary or
supplemental lever, which is pivoted to the first lever just forward of the connec-
tion of the crank with the latter, said supplemental or secondary lever being
lodged in a suitable cavity in the under side of the principal lever, and extending
forward between the fingers of the latter which engage the oscillating cutter, and
bearing upon the middle portion of said cutter. The principal lever is apertured
at a point about the secondary lever to admit the toe or foot of a pressure pin
"dolly," which bears pivotally upon said secondary lever at the lower end,
and at the upper end is exposed to the pressure and adjustment of the tension
screw, which is set through the cap or cover of the housing and adapted to be
screwed up and down to adjust this pressure.
or
One feature of my invention relates to the articulation between the "dolly"
and the tension screw. The latter has its upper end hollowed or cupped, leaving
a marginal flange around the cavity in said upper end, and the tension screw
terminates at its lower end in a convex knob, which enters the socket or cavity
in the upper end of the " dolly," the periphery of the knob being curved in
vertical plane, so that said edge remains in contact with the marginal flange
throughout the oscillation or tilting of the "dolly" in vertical plane. The
co-operating surfaces of the two parts, that is, the lower end surface of the
knob of the tension screw, and the bottom surface of the socket or cavity in the
"dolly," are correlatively shaped, so that the difference in distance of different
points in the convex surface of the knob from a horizontal plane, and the
difference in distance of different points in the bottom of the socket from the
spherical are, of which the center is the center or pivotal point of the foot of the
"dolly," shall compensate for the leaning of the "dolly" as it oscillates back
and forth, carried by the oscillating lever in which it is stepped.
**
As distinguished from other constructions having the same purpose, to wit,
compensation for the oscillating movement, my invention consists in making
the pressure pin or "dolly" pivotally stepped in the lever arm which transmits
pressure to the cutter, and making its head in such form that the center thereof
is nearer the pivotal center of the step than any other point on the head, and
in giving the tension screw a spherical convex lower terminal to bear on the
dolly," and on which the latter will have a rolling action as it oscillates, the
center of curvature of such terminal being in the axis of the screw and as near
as convenient to the plane of junction of the cap and housing.
For the same
general purpose, other devices have heretofore been employed;-such, for example,
as interposing a section of a roller,--that is, a pin having head and foot both
segments of the same sphere, one rolling upon the flat end of the tension screw
and the other upon the pressure lever; or stepping the pin at the lower end on a
pressure lever and providing it at the upper end with a spherical or roller head
operating against the flat end of the tension screw. But all these structures are
dependent for satisfactory action upon the perfect parallelism between the flat
end of the tension screw and the plane of oscillation of the cutter, and are
ineffectual to insure uniformity of pressure between the cutters, if the presence
of a hair or dirt or any slight abrasion or distortion of the parts disturbs such
parallelism. In my improved structure above described, however, the center
or curvature of the cylindrical end of the tension screw being in the axis of the
latter, and midway between the opposite side-bearings of the cap on the body,
any slight dislocation of the cap, caused by the abrasion of its seat or the inter-
position of foreign matter between it and its seat at one side or the other, or any
inequality of such surfaces at one side or the other has practically the effect
of tilting the cover approximately about the center of curvature of the knob, or of
so tilting it slightly, and at the same time slightly elevating that center, neither
of which actions, that is, the tilting nor the elevating, have any effect to
disturb the relations of the parts except in a manner which may be entirely

page_text: compensated by adjustment of the tension screw up or down. That is, such
changes do not cause any variation as the "dolly" rocks in the distance to its
bearing surface on the end of the tension screw directly above the foot.
I construct my improved shearer with minor features other than those above
described substantially according to the principles and methods heretofore in use,
and no description of these familar details is necessary.
The features of novelty in my improved tool are: (1) The combination with
the fixed and oscillating cutter, the actuating pressure arm or lever, the shell
or base in which these parts are mounted and the removable cap and tension screw
set through it, of the pressure foot or "dolly." which is pivotally stepped in the
pressure arm and has a head whose center is nearer the pivotal center of the
step than any other point on the head; the tension screw having its lower end
spherically convex about a center so selected that the form of the "dolly" head
and said tension screw head are together calculated to compensate for the oscilla-
tion of the pin. (2) The ring swivelled about the shaft-hearing and having the
cutter-actuating lever pivoted to as to oscillate horizontally; and in respect to
this feature or portion of the structure,-(3) the particular mode of constructing
the joint so as to afford range of vertical, as well as horizontal, oscillation in
connection with the swivelling action afforded by the ring.
Dated this 13th day of July 1800
JOHN KERWIN STEWART,
By Herbert Haddan & Co.,
Agents to Applicant.
Improvements in Clippers for Shearing Sheep and like Uses.
I, JOIN KERWIN STEWART, of No. 158, Huron Street, in the City of Chicago,
County of Cook, State of Illinois, in the United States of America, Mechanical
Engineer, 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.
1
My present invention consists of certain detail improvements in devices for
pivoting and applying pressure to the cutter-actuating lever arm and pressure
bar of a shearing tool for hair-cutting, sheep-shearing and the like; the purpose
of said device being to adapt the oscillating cutter to accommodate itself more
perfectly to the fixed cutter or comb under the different tensions which may be
employed, and to avoid the inequality of pressure which may otherwise be exerted
upon the oscillating cutter at different parts of its path, rendering the tool, in this
respect, less sensitive to slight derangements of position of the parts, such as is
liable to be caused in the adjustments incident to use, cleaning etc.
My improved shearer comprises a shank or handle A, having at its forward
end, and integral with it, an expanded portion A' which constitutes the body
of the housing for the operating parts: the fixed cutter or comb D, which is rigid
with the housing at the forward and lower side; a cap or upper plate E for the
hcusing; a steel bushing C which, is driven in the sleeve or handle of the
housing and which affords bearing for the operating shaft B, which extends
through the sleeve and has, at its forward end, the crank for the oscillating
cutter G. The crank device consists of an enlarged head or disk B', having the
crank stud pin b', on which is a spherical anti-friction roll 62.
The oscillating motion is communicated to the cutter G, from the crank through
the medium of the lever H, which is pivoted in such manner as to have swivel
movement, and also movement of oscillation both horizontally and vertically

page_text: about its pivotal attachment, which is obtained from the end of the steel bushing
referred to, said bushing being protruded from the sleeve into the housing for that
purpose. The means which I prefer for this pivotal attachment of the lever
comprise a loose ring or sleeve K, which is seated on the reduced inner end of the
bushing and retained by a collar L; the cutter-actuating lever H being forked
to stride the end of the bushing and the ring, and pivoted to the latter at the
ends of both fork-arms, one above and the other, H, below the ring and bushing,
the pivotal attachment being of such nature as to permit a slight vertical
oscillation about the vertical pivot, while a swivelling movement, it will be
observed, is obtained by virtue of the ring to which it is thus pivoted, as shown in
Fig. 4 which is a section on line 4--4 of Fig. 1. The vertical oscillation may be
obtained by making the pivotal joint comprise a slightly, and almost imper-
ceptibly elongated slot for either or both of the pivot pins M M, but for more
perfect accomodation in this respect I may construct the joint, as shown in
Fig. 5, by forming on the end of the steel bushing, a spherical swell or knob-like
seat by means of a ring P, which is also retained by the collar L, and making the
ring K. which is swivelled on the bushing to fit this seat,-forming it in two
parts K K (see Fig. 6 which is a section on line 6-6 of Fig. 5) so that it may
be assembled about the latter, thus producing a ball joint with sufficient range of
oscillation in a vertical plane, the forked lever H being pivoted to the ring as
in the other construction. The spherical anti-friction roller of the crank
operates in a vertical cylindrical track-way h, formed in the lever arm H forward
of the pivoted fork-ends. The lever engages the oscillating cutter by fingers H'H'
at the the forward end, taking into suitable apertures in the cutter and pressure
is transmitted through the lever to the oscillating cutter by means of the secondary
or supplemental lever H³, which is pivoted to the lever H at 3, just forward of
the connection of the crank with the latter, said supplemental or secondary lever
being lodged in a suitable cavity in the under side of the lever H, and extending
forward between the fingers H H of the latter, and bearing upon the middle
portion of said cutter. The principal lever H is apertured at a point above the
secondary lever H3 to admit the toe or foot of a pressure pin or "dolly" J.
which bears pivotally at ³° upon said secondary lever at the lower end, and at
the upper end is exposed to the pressure and adjustment of the tension screw F.
which is set through the boss E of the cap or cover E of the housing and adapted
to be screwed up and down to adjust this pressure.
One feature of my invention relates to the articulation between the "dolly"
and the tension screw. The former has its upper end hollowed or cupped, leaving
a marginal flange J¹ around the cavity in said upper end, and the tension screw
terminates at its lower end in a convex knob F¹, which enters the socket or
cavity in the upper end of the dolly, the periphery of the knob being curved in
vertical plane, so that said edge remains in contact with the marginal flange J¹
throughout the oscillation or tilting of the dolly in vertical plane; that is, in
the form of a middle segment of a sphere whose diameter is that of the socket
in the head of the dolly, and whose center is in the axis of the tension screw, as at
the point f. The cooperating surfaces of the two parts, that is, the lower end
surface of the knob of the tension screw and the bottom surface of the socket or
cavity in the dolly, are correlatively shaped, so that the difference in distance of
different points in the convex surface of the knob from a horizontal
plane, and the difference in distance of different points in the bottom
of the socket from the spherical arc, of which the center is the
center or pivotal point of the foot of the dolly, shall compensate
for the leaning of the dolly as it oscillates back and forth, carried by the oscillating
lever in which it is stepped. Specifically referring to the drawings, the center of
spherical curvature of the head of the tension screw is at f¹ in the axis of
ihe tension screw, and considerably above the center f, so that the vertical distance
from the spherical end of the tension screw to a horizontal plane containing the
center f, decreases from the axis of the screw outward. The bottom of the socket

page_text: of the dolly may be spherically curved about a center much more remote than f¹.
and it may be flat, that is, curved about a center infinitely remote, so that the
distance of points on this surface from the end of the foot of the dolly increases
from the center of the socket outward.
Thus it will be seen that the form of the two surfaces, the bottom of the socket
and the head of the tension screw-may be so related so to effect the compensation
stated.
As distinguished from other constructions having the same purpose, to wit:
compensation for the oscillating movement, my invention consists in making
the pressure pin or "dolly" pivotally stepped in the lever arm which transmits
pressure to the cutter, and making its head in such form that the center thereof
is nearer the pivotal center of the step than any other point in the head, and
in giving the tension screw a spherical convex lower terminal to bear on the
dolly, and on which the latter will have a rolling action as it oscillates, the
center of curvature of such terminal being in the axis of the screw, and as near
as convenient to the plane of junction of the cap and housing. For the same
general purpose, other devices have heretofore been employed:such for example,
as interposing a section of a roller, that is, a pin having head and foot both
segments of the same sphere, one rolling upon the flat end of the tension screw
and the other upon the pressure lever or stepping the pin at the lower end on a
pressure lever and providing it at the upper end with a spherical or roller head
operating against the flat end of the tension screw. But all these structures are
dependent for satisfactory action upon the perfect parallelism between the flat
end of the tension screw and the plane of oscillation of the cutter, and
ineffectual to insure uniformity of pressure between the cutters, if the presence
of a hair or dirt or any slight abrasion or distortion of the parts disturbs such
parallelism. In my improved structure above described, however, the center
of curvature of the spherical end of the tension screw being in the axis of the
latter, and midway between the opposite side-bearings of the cap on the body,
any slight dislocation of the cap. caused by the abrasion of its seat or the inter-
position of foreign matter between it and its seat at one side or the other, or any
inequality of such surfaces at one side or the other, has practically the same effect
of tilting the cover approximately about the center of curvature of the knob, or of
so tilting it slightly, and at the same time slightly elevating that centre neither
of which actions, that is, the tilting nor the elevating, have any effect to
disturb the relations of the parts except in a manner which may be entirely
compensated by adjustment of the tension screw up or down.
That is, such changes do not affect the distance (which changes as the dolly
rocks and whose change is compensated by the curvature of the tension screw,
see Figure 8), from the point of bearing of the dolly on the end of the tension
screw to the step in which the dolly rests directly below such point of bearing,
as may be.
This result is further assisted, that is, the disturbing effect of abrasion or
interposition of foreign matter at the joint between the housing-cap is minimized,
by the construction shown, in which the cap seats on the housing and is secured
thereto at the middle point (see bolt e Figs. 1 and 5) approximately in the hori-
zontal plane of the cooperating surfaces of the tension screw and dolly, and the
laterally most remote points of bearing between the cap and housing (see side-
bolt ee, Fig. 3) are also not far removed from the same horizontal plane.
I construct my improved shearer with minor features other than those above.
described substantially according to the principles and methods heretofore in use,
and no description of these familar details is necessary.
Having now particularly described and ascertained the nature of this said
invention, and in what manner the same is to be performed, I declare that what
I claim is
1. In a shearing tool, in combination with the fixed cutter or comb. the

page_text: oscillating cutter and its actuating pressure arm or lever; a shell or base in which
said parts are mounted and with which the comb is rigid; a removable cap and
a tension screw set through the cap; a pressure pin pivotally stepped in the
pressure arm and provided with a head whose center is nearer the pivotal center
of the step than any other point in said head; the tension screw having a spherical
convex lower end on which the pressure pin bears and has a rolling action, the
curvature of the tension screw terminal and form of the pressure pin head being
together calculated to compensate for the oscillation of the pin.
2. In a shearing tool, in combination with a fixed comb or cutter, the oscillat-
ing cutter a shaft from which movement is communicated to said cutter; a ring
swivelled about the bearing of the shaft, and the cutter actuating lever pivoted
to said ring at a line substantially at right angles to the plane of oscillation of the
cutter.
3. In a shearing tool, in combination with a fixed comb or cutter, the oscillating
cutter; the shaft from which such cutter derives its motion; a ring swivelled
about the bearing of such shaft: a crank on said shaft forward of said bearing;
the cutter-actuating lever pivoted to the ring at a line at right angles to the plane
of oscillation of the cutter, and engaged and actuated by the crank forward of
said pivot.
4. In a shearing tool, in combination with the fixed comb or cutter, the oscillat-
ing cutter, the driving shaft journaled in bearings fixed with respect to the fixed
cutter and having a crank-wrist-pin at the forward end the cutter-actuating lever
engaging at the forward end the oscillating cutter and being engaged inter-
mediate the same by the crank wrist being extended at the rear both above and
below the shaft-bearing and pivoted to the latter at diametrically opposite points
thereon in a line at right angles to the plane of oscillation of the cutter.
5. In a shearing tool,. in combination with a fixed comb or cutter, the driving
shaft the oscillating cutter and its actuating lever, the fulcrum of said lever arm
being provided by means of a ring swivelled about the bearing of the shaft and
to which the lever is pivoted in a line at right angles to the plane of oscillation
of the cutter.
6. In a shearing tool, in combination with a fixed comb or cutter, the oscillating
cutter and its actuating lever arm, the fulcrum of said lever being formed by
means of a ring having a spherical seat about the bearing of the shaft and
provided with diametrically opposite pivot studs for the lever, in a line at right
angles to the plane of oscillation of the cutter.
Dated 41: 10+1
1000
JOHN KERWIN STEWART,
Herbert Haddan & Co.,
Agents to Applicant, 18, Buckingham Street, Strand, London, W.C.