Improvements in the Method of Generating Bevel Gear Teeth and in Apparatus Employed therein.
Year: 1894

page_text: Date of Application, 8th Jan., 1894
Complete Specification Left, 8th Oct., 1894-Accepted, 5th Jan., 1895
PROVISIONAL SPECIFICATION.
Improvements in the Method of Generating Bevel Gear Teeth and
in Apparatus Employed therein.
A communication by GEORGE B. GRANT, of Lexington, in the State of
Massachusetts, one of the United States of America, Manufacturer.
I ALFRED GEORGE BROOKES of 55 and 56 Chancery Lane, in the County of
London, Chartered Patent Agent do hereby declare the nature of this invention to
be as follows:-
This invention relates to bevel gear teeth and the generation of the same.
Generated gear teeth may be distinguished from cut gear teeth in that cut teeth
are made to a copy of the tooth curve desired, such copy being either a cutter, or
a templet previously formed as nearly as may be to the curved form; while
generated teeth are formed by a theoretical adaptation of mechanism so that it will
properly form or generate a tooth in accordance with the theory of that form.
The invention is based upon the principle that if the pitch cones of two bevel
gears be rolled frictionally together without slip, any tooth form on one pitch
cone will mate and run with a conjugate tooth form on the other pitch cone.
Consequently when two pitch cones are rolled together, any tooth form on one
pitch cone when constituted a cutting tool, will shape a tooth form on the other
pitch cone which is conjugate to it; therefore a cutting tool on one pitch cone
when shaped to correspond with the desired flank of a bevel gear tooth will
necessarily generate a face on the other pitch cone which is conjugate to it and to
the flank of the tooth with which the shape of the cutting tool corresponds, the
cutting tool thus describing a surface which corresponds with the flank of a tooth
of a mating gear.
A machine for generating bevel gear teeth in accordance with the foregoing
principle is constructed to give to the cutting tool and the gear blank a relative
movement as of the pitch cones of the two mating gears rolling one upon the other,
the cutting tool, being imagined as on one of the pitch cones, while the gear blank
is attached to the other pitch cone.
This relative motion may be obtained by imagining the axes of the pitch cones as
fixed, a rolling movement being given both to the cutting tool and the gear blank;
or one of the pitch cones may be imagined as stationary, while the other pitch
cone carrying the gear blank or the cutting tool is rolled about it.
For most practical purposes it is preferred to have one imaginary pitch cone
stationary and carrying the moving cutting tool, while the other imaginary pitch
cone constituting the gear blank is rolled about it, the cutting tool thus describing
the tooth flank surface of a gear with which the rolling gear blank is to work.
A plane cutting tool having a straight cutting edge or flat surface is in every
way the most simple cutting tool to employ in a machine, and it is therefore
preferred to employ such a tool in my machine, such a tool producing, however, a
bevel gear tooth, which, though it embodies the essential characteristics above
named, yet is of a shape which so far as my correspondent is aware is entirely new,
such tooth consisting of flanks which are planes and faces which are curved
surfaces conjugate to planes.
This form of tooth differs from any bevel gear tooth heretofore known to my
correspondent, in that its curved tooth surface differs from any other, and my

page_text: correspondent has therefore named the tooth embodying such surface "a planoid
tooth," such name being derived from its peculiar relation to the plane, as will be
more fully hereinafter set forth.
This invention broadly, therefore, consists in a machine for generating bevel
gear teeth, comprehending a cutting tool; a holder for the gear blank; and
actuating devices to relatively change the positions of the said tool and holder as
of the pitch cones of the gear blank and its mating gear (the latter pitch cone
carrying the cutting tool) rolling one upon the other, whereby the said tool
acting on the said blank is caused to generate a curved tooth surface conjugate to
the flank of a mating tooth with which its cutting edge coincides.
Dated the 8th day of January 1894.
WM. BROOKES & SON,
55 & 56, Chancery Lane, London, Agents for the Applicant.
Improvements in the Method of Generating Bevel Gear Teeth and
in Apparatus Employed therein.
A communication by GEORGE B. GRANT, of Lexington, in the State of
Massachusetts, one of the United States of America, Manufacturer.
I Alfred George BROOKES of 55 and 56 Chancery Lane in the County of
London, Chartered Patent Agent 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:-
This invention relates to bevel gear teeth and the generation of the same.
Generated gear teeth may be distinguished from cut gear teeth in that cut teeth
are made to a copy of the tooth curve desired, such copy being either a cutter,
or a templet previously formed as nearly as may be to the curved form; while
generated teeth are formed by a theoretical adaptation of mechanism so that
it will properly form or generate a tooth in accordance with the theory of
that form.
This invention is based upon the principle that if the pitch cones of two bevel
gears be rolled frictionally together, without slip, any tooth form on one pitch
cone will mate and run with a conjugate tooth form on the other pitch cone.
Consequently when two pitch cones are rolled together, any tooth form on one
pitch cone when constituted a cutting tool, will shape a tooth form on the other
pitch cone which is conjugate to it; therefore a cutting tool on one pitch cone
when shaped to correspond with the desired flank of a bevel gear tooth will
necessarily generate a face on the other pitch cone which is conjugate it to and to
the flank of the tooth with which the shape of the cutting tool corresponds the
cutting tool thus describing a surface which corresponds with the flank of a tooth
of a mating gear.
A machine for generating bevel gear teeth in accordance with the foregoing
principle is constructed to give to the cutting tool and the gear blank a relative
movement as of the pitch cones of the two mating gears rolling one upon the other,
the cutting tool, being imagined as on one of the pitch cones, while the gear blank
is attached to the other pitch cone.
This relative motion may be obtained by imagining the axes of the pitch cones as
fixed, a rolling movement being given both to the cutting tool and the gear blank;
or one of the pitch cones may be imagined as stationary, while the other pitch cone
carrying the gear blank or the cutting tool is rolled about it.
For most practical purposes it is preferred to have one imaginary pitch cone

page_text: stationary and carrying the moving cutting tool, while the other imaginary
pitch cone constituting the gear blank is rolled about it, the cutting tool thus
describing the tooth flank surface of a gear with which the rolling gear blank is
to work.
A plane cutting tool having a straight cutting edge or flat surface is in every
way the most simple cutting tool to employ in a machine, and it is therefore
preferred to employ such a tool in the machine, such a tool producing, however, a
bevel gear tooth which, though it embodies the essential characteristics above
named, yet is of a shape which so far as my correspondent is aware is entirely new
such tooth consisting of flanks which are planes and faces which are curved
surfaces conjugate to planes.
66
This form of tooth differs from any bevel gear tooth heretofore known to my
correspondent in that its curved tooth surface differs from any other, and my
correspondent has therefore named the tooth embodying such surface a planoid
tooth," such name being derived from its peculiar relation to the plane, as will be
more fully hereinafter set forth.
This invention broadly, therefore, consists in a machine for generating bevel
gear teeth, comprehending a cutting tool; a holder for the gear blank; and
actuating devices to relatively change the positions of the said tool and holder as
of the pitch cones of the gear blank and its mating gear (the latter pitch cone
carrying the cutting tool) rolling one upon the other, whereby the said tool acting
on the said blank is caused to generate a curved tooth surface conjugate to the
flank of a mating tooth with which its cutting edge coincides, substantially as will
be described.
Other features of this invention will be hereinafter described and particularly
pointed out in the claims.
Figures 1 to 6 are diagrams illustrating my improved process of generating bevel
gear teeth, the figures also illustrating a tooth formed by my improved process,
having plane flanks and faces which are curved surfaces conjugate to such plane
flanks;
Fig. 7 a side elevation of the machine for generating bevel gear teeth in
accordance with my improved process the gear blank upon which the teeth are to
be generated being in section;
Fig. 8, a plan view, and Fig. 9, a side elevation of the machine shewn.
Referring first to Figs. 1 and 2 of the drawings, my improved process of
generating bevel gear teeth may be described in detail as follows:-
The teeth are represented as outlined upon the surface of a sphere, the points a
and representing the axes of the pitch cones of the two bevel gears which are to
work together; c and d, arcs of the pitch circles or surfaces of the pitch cones,
which with the pitch point e lie in a great circle of the sphere.
Let b, d, represent the pitch cone of the gear blank, and a-c, the pitch cone of
a gear with which the gear being cut is to work. Now, if a tooth form T being
fixed to the pitch cone a-c, Fig. 1, and the two pitch cones rolled together in the
direction of the arrows as the pitch cones of two working bevel gears would roll
together, it is clear that the form T during the rolling movement will generate on
the pitch cone b-d a tooth form or surface which as shewn in Fig. 2 must be
conjugate to it, that is the generated form Fig. 2 will be such that it will contact
with the generating form T at all times while they work together during the
rolling movement of the pitch cones. In Fig. 2 the axes a-b of the two pitch
cones are supposed to be fixed, the pitch cones having been rolled together about
these fixed axes; but the tooth form T on the pitch cone a-c, will generate
precisely the same form or surface on the pitch cone b-d if the pitch cone a- be
imagined as stationary and the cone 6-d rolled about it, or vice versa, if the pitch
cone bd be considered as fixed, and the pitch cone a-c be rolled about it.
If now the form T be shaped to correspond with the form which it is desired the
completed tooth on b-d shall partake, it follows that if the form T be considered.
a moving cutting tool, whether reciprocating, rotating or other form, and the pitch

page_text: cone b-d, considered the gear blank upon which the teeth are to be generated if
the pitch cone b-d be rolled about the pitch cone a-c, the moving cutting tool T
will cut or generate a tooth surface on the gear blank which must be conjugate to
it and must therefore be conjugate to a tooth similar in shape to the cutting tool
on a mating bevel gear which works with the gear b―d.
In practice, however, it is not practicable to employ a cutting tool having the
full form of a tooth, it being necessary to utilize a planing or milling tool which
will generate one side of a tooth only at a time, such tool having two cutting edges
or sides, one of which will be utilized in generating one face of each gear tooth,
while the other side will be utilized to generate the opposite face of each tooth, the
cutting tool being shifted at the proper time to bring its opposite acting side into
proper position with relation to the axis of the pitch cone of the gear.
As hereinbefore stated, it also is very desirable to employ the simplest and
most inexpensive form of cutting tool and one which may be easily sharpened,
and by the process of generating bevel gear teeth described my correspondent is
enabled to use a tool having a perfectly straight cutting edge or side, such a tool
however producing a form of tooth hitherto unknowu to him and which he has
termed a "planoid tooth" the name being derived from its peculiar tooth surface.
This planoid tooth surface may be strictly defined as that surface which is formed
upon a body attached to the outside of an imaginary cone by a tool attached to
the inside of another imaginary cone and having a motion describing a plane
substantially through its apex, the two imaginary cones being tangent and rolling
one upon the other.
The "planoid" tooth is represented in the diagrams Figs. 3 to 6 inclusive, partially
in full and partially in dotted lines, representing the completed tooth while the full
lines illustrate the process of generating the tooth, and referring to said figures
ff, represent the plane flanks of the mating teeth and 9, g, the curved faces
conjugate to the plane flanks.
A peculiar feature of the "planoid" tooth is that the same tool may be used to
cut or generate not only the flanks of the tooth but to sweep or generate the
curved faces as well, for after the tool has cut a flank with the two pitch cones at
rest, if the pitch cones be rolled together, the same tool will sweep or generate
a curved face on the tooth which is conjugate to it and to a flank of a
mating tooth.
This will be best understood by referring to Fig. 3, wherein the two pitch
cones ac and -d are supposed to be at rest and the cutting tool t2 is supposed
to have been moved to make a direct cut into the gear blank represented by the
pitch cone bd to form a flank f of a tooth. If after the cut has been made to
the required depth the tool be withdrawn so that its end lies in the surface of the
pitch cone ac, and the pitch cone b-d be rolled about the pitch cone a-c into
its position Fig. 4, the cutting side t* of the tool t will sweep up or generate a
curved face which must be conjugate to the plane cutting side of the tool, and
also to the plane flank of a mating tooth in the imaginary flank surface of which
the cutting side of the tool moves. This operation may be repeated until one
surface of each tooth is properly generated, when the tool will be shifted as will be
more fully hereinafter described, to generate in like manner the opposite surface
of the tooth to complete the same as indicated by dotted lines.
The flanks of the " planoid" teeth need not necessarily lie in any particular
plane, but for the best practical results both as regards the process of generating
the tooth and the practical operation of the same thereafter, it is preferred to have
the flanks of the teeth radial planes as illustrated by Figs. 5 and 6, referring to
which, in Fig. 5 the two pitch cones a-c and b-d are represented as stationary,
the plane cutting tool having its cutting side moving in a plane radial to the axis
of the pitch cone a-c having made a direct cut into the gear blank to form a
radial flank of a tooth thereon. The tool will then preferably be withdrawn as
described until its end moves in the surface of the pitch cone a-c when the pitch
cone bd will be moved to the right and given a inovement with relation to the

page_text: cutting side of the tool as of its pitch cone rolling about the fixed pitch cone a-c,
when the said cutting side will sweep up or generate a curved face g which must be
conjugate to it and to the radial flank of a mating tooth.
One form of machine to form or generate the planoid teeth illustrated in Figs. 5
and 6 by the process described is represented in Figs. 7 to 9 inclusive, wherein
A represents a bed of suitable shape and construction to sustain the working parts;
B represents an oscillating plate or carrier pivoted at B' on the bed and carrying
the curved arc or arm B2 in which is formed a suitable guide-way B³ for the spindle
head C made adjustable on and with relation to the said arc by suitable adjusting
devices or bolts C₁, said spindle head carrying the spindle stock C² made
horizontally adjustable with relation to the head C and held in adjusted position
by suitable clamping devices or screws Cx. The spindle stock C receives the
spindle or gear blank holder i fitted at its front end to receive the usual arbor to
support the gear blank n upon which the bevel gear teeth are to be cut or generated,
and the said holder at its opposite end has fast upon it a master wheel ¹ provided
with worm teeth upon its periphery in mesh with and driven by a worm k repre-
sented in dotted lines in the drawings Fig. 8, and fast upon a worm shaft k¹
journaled in a bracket bolted or otherwise secured to the adjustable spindle
stock C². The worm shaft k¹ in the present instance is fitted at its outer front end
with a crank k³ provided with a movable pin k*, see Fig. 8, which pin is adapted to
enter one or another of a series of circumferentially arranged holes in a sprocket
wheel loosely mounted on the shaft k and connected by a sprocket chain with
and driving a sprocket wheel m fast on a worm shaft m' journaled in suitable
bearings in a bracket or brackets m², formning part of or attached to the oscillating
plate or carrier B, see Fig. 7, said worm shaft having a worm m³ in mesh with a
curved sector m* on the edge of the bed A. By withdrawing the pin * on the
crank from the hole 1x on the sprocket wheel with which it is in engagement
either of the worm shafts k' or m' may be rotated independently of each other the
worm shaft when rotated acting through the master wheel to cause rotation
of the gear blank n about its axis 1-2; while rotation of the worm shaft m' acts
through its worm and the curved sector m' on the bed to cause rotation or oscillation
of the carrier B carrying the holder i and gear blank about its vertical axis 3-4,
the two axial lines 1-2, 3-4, intersecting each other at the point 5, which forms
the apex of the machine.
R represents the tool head mounted on the bed A and made adjustable thereon
to vary the position of the cutting tool with relation to the blank, by means of
suitable clamping bolts r which pass through slots in the foot of the tool head
said head being moved for adjustment by means of a threaded shaft fitted at its
outer end with an operating handle, rotation of the handle and shaft in one or
the other direction moving the head R toward or from the apex of the machine.
A rotatable tool holder S journaled in the bead R, has its periphery provided
with teeth which are engaged by a worm & fast on a shaft s journaled in suitable
bearings & carried on the head, said shaft s' being fitted with a crank or operating
handles by which it may be rotated and the tool holder thereby revolved about
its axis. The tool holder S has fixed to it a guide bar t on which slides the
tool carriage t having clamped to it in suitable manner a planing tool t, said
carriage being reciprocated on the guide-bar, by a connecting rod t jointed to
and operated by a crank t' on a driving shaft to journaled in suitable bearings in
the guide bar and driven by a belt te, as shewn.
The imaginary cone represented by the dotted lines 6, 5, 7, represents the pitch
cone of the gear blank being cut while the imaginary cone represented by the
dotted lines 6, 5, 8, represents the pitch cone of the mate with which it is
supposed to work and in practice the cutting tool t2 will preferably be set to
move in the plane of the axes 1-2, 3-4 this position of the cutting tool
generating the radial form of the "planoid " tooth referred to and the tool will
also be preferably set so that its lower cutting edge will move in a line extended
through the apex 5 of the machine, so as to produce a tooth having all its elements

page_text: converging toward the apex of the pitch cone of the gear blank, although this
latter is not essential, as will be more fully hereinafter described.
The preferable manner of operating the machine for generating ordinary bevel
gear teeth is as follows:-The tool head R will first be adjusted so that the
lateral cutting side of the tool t2 when the same is reciprocated, will move in the
vertical plane of the axes 1-2, 3-4, and preferably with its lower cutting edge in
such position that it will move in a line passing through the apex 5 of the machine;
the tool will then he turned back into its dotted line position Fig. 7 by rotation of the
cranks and the tool holder S. The gear blank n will then be fastened upon the end
of the holder i and the spindle stock C2 adjusted horizontally, so that the apex of the
pitch cone of the gear blank will coincide with the apex 5 of the machine. With the
gear blank held stationary the shaft to will now be set in motion by means of the belt (
to give a reciprocating movement to the cutting tool t2 and the operator by grasping
the handle on the worm shaft will rotate the latter to cause the tool holder S to be
revolved in the direction of the arrow Fig. 7 to gradually feed the reciprocating
cutting tool into the gear blank and causes the tool to make a direct radial cut in
the blank as illustrated by Fig. 5, which will form one of the radial flanks of a
tooth. When the flank has been cut to the desired depth, the tool holder S will by
means of the crank s be preferably revolved to withdraw slightly the reciprocating
cutting tool from the cut made, the point of the tool being preferably withdrawn
to about the pitch circle of the gear blank, when the operator by grasping the
crank k³ on the worm shaft k¹ will gradually rotate the latter, and with the pin k
in engagement with one or another of the holes * on the sprocket wheel l, will also
cause a corresponding rotation of the worm shaft m', the rotation of the said worm
shafts causing a rotative movement of the gear blank n about its axis 1-2, corre-
sponding to the rolling motion of the pitch cone about its axis, and also a movement
bodily of the carrier B and the gear blank n carried by it, about the vertical
axis 3-4, giving to the blank a movement with relation to the cutting tool,
corresponding to the rolling movement of the pitch cone of the gear blank upon
the pitch cone of a mating gear, causing the tool to sweep or form a curved surface
upon one side of the tooth, as in Fig. 6, which must be conjugate to the plane in
which the lateral cutting side of the tool is which is a radial plane with relation to
the axis 3-4 of the imaginary cone of the gear with which the gear blank is to
work, and such curved face must necessarily be conjugate to the radial flank of a
gear tooth on the mating wheel. One side of one tooth being thus formed, the
handle will be rotated in the opposite direction, to return the carrier B to its
normal position, when the pink will be withdrawn from the hole * in the sprocket
wheel with which it was in engagement, and the handle k³ turned to rotate the
spindle to revolve the gear blank n into proper position for the cutting of a
corresponding face of the next tooth, when the cutting tool holder S will be again
revolved in the direction of the arrow to bring the reciprocating cutting tool down
to cause it to make a cut in the gear blank and the gear blank subsequently given
the rolling and rotative movement previously described for the purpose of shaping
a second tooth, these operations being continued until one face of each tooth on the
flank has been properly generated. The head R will then be adjusted or moved to
the left Fig. 5 to thereby bring the opposite lateral cutting edge of the tool 2 in a
radial plane with the axes a and b of the pitch cones, when the machine will be
manipulated in precisely the manner herein before described so that the tool will
cut or form the opposite sides of each of the teeth on the gear blank, the rotation
of the worm shafts k, m³, however being in this second operation in the opposite
direction from that previously described because the cutting tool must sweep a
curved surface opposite from the surface swept by it in the first operation.
If the angle of the gears is to be other than a right angle, the head C will be
adjusted vertically on the arc B2, to thereby change the angle of the intersecting
axes 1-2 and 3-4, from a right angle as shown in the drawings to the desired
augle.
The relative diameters of the sprocket wheels Zand m will be such that the

page_text: oscillating movement of the carrier B to give the rolling motion to the gear blank,
will be in proper ratio to the rotative movement about its axis given to the gear
blank by the master wheel i and its worm k, these sprocket wheels being made
changeable so that the relative motion of the carrier B and spindle i may be changed
to accommodate any desired number of teeth upon the gear blank, and instead of
the sprocket chain herein shown, I may use a series of change gears or other
suitable connecting devices.
While I have herein shown the lower edge or point of the cutting tool as moving
in a line passing through the apex 5 of the machine, still such is not essential, for
the movement of the cutting tool may be theoretically in any other direction.
This invention is not limited to the particular machine herein shown and described
for generating bevel gear teeth, for the machine may be varied in many respects
without departing from the spirit and scope of this invention so long as the gear
blank and cutting tool are given a relative movement as of the pitch cones of the
blank and mating gear rolling one upon the other, whereby the cutting tool
generates a curved tooth surface conjugate to the flank of a mating tooth with
which the cutting edge of said tool coincides.
While I have herein shown and described a machine for generating a planoid
tooth having plane radial flanks and curved planoid faces conjugate to radial flanks,
still I do not limit my invention in this respect. The tooth generated by the
machine herein shown is only one specific form of the planoid tooth, for the flanks
of the teeth if planes may be any planes desired other than radial planes, the
planoid face in each case being conjugate to the particular plane flank employed.
Generally speaking, the "planoid "tooth is one having flanks which are planes
and faces which are curved surfaces conjugate to the plane flanks of the mating
teeth, meaning by conjugate such a curved surface as will work perfectly with the
mating flank face during operation of the gears. The difference between the two
specific forms of the tooth shown in Figs. 3 and 5 of the drawings, or between any
other two specific forms being a difference of convenience rather than a difference
in theory.
The form of "planoid " tooth represented in Figs. 5 and 6 is a close approach to
the form of tooth commonly known as the "radial-flanked epicycloidal" tooth in
very common use; but it is in fact an essentially different form of tooth.
"
Referring to Fig. 3, the line of action (or the line in which the point of contact
travels) of the "planoid " tooth is a kite-shaped curve a³ which is tangent to the
circle to which the straight flanks f are also tangent; and for a "planoid
tooth having radial flanks the line of action Fig. 5, passes through the axis b,
but is still non-circular in form.
The line of action of the true "epicycloidal" tooth is always a circle. The
flank is never a true radial plane, but when the line of action is a circle passing
through the axis b, the flank is a curved surface that approximates a radial plane.
The practical difference is material, for while the plane flank of the "planoid
tooth is easily formed with common tools, the true epicycloidal flank is difficult to
form and requires special tools.
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 machine for generating bevel gear teeth, comprehending a cutting tool; a
holder for the gear blank; and actuating devices to relatively change the positions
of the said cutting tool and holder as of the pitch cones of the gear blank and its
mating gear (the latter pitch cone carrying the cutting tool) rolling one upon the
other, whereby said cutting tool acting upon said blank is caused to generate a
curved tooth surface conjugate to the flank of a mating tooth with which its cutting
edge coincides, substantially as described.
2. A machine for generating bevel gear teeth, comprising a straight edged
cutting tool; a holder for the gear blank; and actuating devices to relatively

page_text: change the positions of the said cutting tool and holder as of the pitch cones of the
gear blank and its mating gear (the latter pitch cone carrying the cutting tool)
rolling one upon the other, whereby said cutting tool acting upon said blank is
caused to generate a curved tooth surface conjugate to the plane flank of a mating
tooth with which its cutting edge coincides substantially as described.
3. In a machine for generating bevel gear teeth, a cutting tool, a holder for the
gear blank to be cut, and actuating devices to relatively change the positions of the
said tool and holder whereby the tool acting on the blank is caused to generate a
tooth surface having a plane flank and a curved face conjugate to the plane flank
of a mating tooth, substantially as described.
4. A machine for generating bevel gear teeth, comprehending a cutting tool, a
bolder for the gear blank, and actuating mechanism to give to the gear blank a
motion with relation to the cutting tool as of the pitch cone of the gear blank
rolling upon the pitch cone of a mating gear, substantially as described.
5. A machine for generating bevel gear teeth comprehending a moveable cutting
tool, a holder for the gear blank and actuating mechanism to give to the gear
blank a motion with relation to the cutting tool as of the pitch cone of the gear
blank rolling upon the pitch cone of a mating gear, substantially as described.
6. In a machine for generating bevel gear teeth, a holder for the gear blank;
mechanism to rotate the holder and gear blank about the axis of the latter, and
independent mechanism to move the holder and blank about an axis at an angle to
the axis of the gear blank and passing through the apex of the pitch cone of the
blank, and connecting devices between the said mechanisms whereby either may
be operated independently of the other and also operated one by the other,
substantially as described.
7. In a machine for generating bevel gear teeth, a holder for the gear blank,
mechanism to move the same about its axis, and also about an axis intersecting said
axis, and a moveable cutting tool having its cutting side moving in a plane passing
through the latter or intersecting axis, substantially as described.
8. In a machine for generating bevel gear teeth, a holder for the gear lank,
mechanism to move the same about its axis, and also about an axis intersecting said
axis, and a moveable cutting tool having two cutting sides, the said cutting tool and
holder being adjustable one with relation to the other to cause one or the other of
the cutting sides of the tool to move in a plane passing through the latter or
intersecting axis, substantially as described.
9. In a machine for generating bevel gear teeth, a bed, a carrier pivotted
thereon, a spindle stock on said carrier and a spindle therein to support the gear
blank, a sector on the bed, a co-operating worm on the carrier, and mechanism
attached to the carrier and actuated by rotation of the worm to cause rotation of
the spindle gear blank, substantially as described.
10. In a machine for generating bevel gear teeth, a bed, a carrier pivotted
thereon, a spindle stock on said carrier, and a spindle therein to support the gear
blank, a sector on the bed, a co-operating worm on the carrier, a worm wheel to
rotate the spindle, a worm to actuate the same, and a variable connection between
said worms, substantially as described.
11. In a machine for generating bevel gear teeth, a bed, a holder for the gear
blank, mechanism to give to the gear blank a rolling motion, a reciprocating tool
carriage, and a guide therefor, made adjustable to thereby vary the line of motion
of the tool radially with relation to the gear blank substantially as described.
Dated the 5th day of October 1894.
WM. BROOKES & SON,
55 & 56, Chancery Lane, London, Agents for the Applicant.