Improvements in Angle Gearing.
Year: 1898

page_text: Improvements in Angle Gearing.
A communication from James Henry Sager, of 7, Lake View Park, in the City of
Rochester, in the State of New York, one of the United States of America,
Manufacturer.
I, PHILIP MIDDLETON JUSTICE, of 55 and 56, Chancery Lane, London, in the County
of Middlesex, Chartered Patent Agent, do hereby declare the nature of this inven-
tion, as communicated to me by my foreign correspondent, to be as follows:-
The object of my invention is to produce angle gearing having certain advantages
due to its construction as hereinafter described. I have produced the gearing
hereinafter set forth in order to avoid many of the difficulties found in prior angle
gears and to produce an easy running and efficient mechanism.
The mechanism consists of a toothed wheel carried by a suitable shaft which is
set in proper bearings, and a pin face gear carried by another shaft, also set in
proper bearings. The two shafts may be set at various angles, acute, obtuse, or at
right angles to each other. The pin face gear consists of a disk set transversely upon
its shaft, and having upon said disk a series of equidistant pin teeth arranged in a
circle around the center of revolution of the disk, with their axes projecting from
the disk. I prefer to use cylindrical pins whose axes are at right angles to the face
of the disk and therefore are parallel to the axis of their shaft; but as will be obvious
from the following description the pins may have other angles with reference to
the face of the disk, or may be of other forms than cylindrical, including conical,
oval and spherical. These pins may be solid or may consist of rollers set upon
central pins. The roller may be hardened and the pin may be of softer material.
The pin is rigidly fixed to the disk in any suitable manner.
The gear wheel forming the other member of the pair of angle gears has a series
of equidistant teeth for engagement with the pins, of the same pitch as the pins.
These teeth may be set either upon the side face of the wheel or may be formed upon
the periphery of the wheel. When the teeth are formed upon the periphery of the
wheel the mechanism occupies less space than when the teeth are on the face of
the wheel. The teeth are of a modified wedge shape having the medial plane of
each tooth transverse to or across the plane of rotation of the wheel, and the apex
of the wedge (whether truncated or not) points or is directed transversely to said
plane of rotation. When the teeth are not skew teeth nor the wheel a skew wheel,
the medial plane of each tooth is perpendicular to the plane of rotation of the wheel.
The interdental spaces at the bases of the teeth have sides which are not radial as
to the wheel but which are at said base line parallel to each other and are separated
by a distance only slightly greater than the diameter of the pin. This difference
being for the purpose of permitting clearance of the pin without binding in the
interdental spaces.
The contour of the said faces of the teeth upon the gear wheel
and the pitch of said teeth are developments of the moving pins upon the revolving
disk when the velocity of the tooth circle equals the speed of rotation of the circle in

page_text: which the bases of the pins are set; or, in other words, when the two members of
the gear have a uniform rate of velocity. The contour of the side faces of the teeth
and the pitch of said teeth will vary according to the sizes of the two members of
the gear, and of the pins upon the member bearing them...
".
A gearing may be produced according to my invention without involving this
uniform rate of velocity. The side surfaces of the teeth are warped or twisted
surfaces upon which the pin, if on the driving member, has always a line contact
from the position of first engagement at the entrance into the interdental spaces,
with an approaching action, to the root or base of the tooth at the position of deepest
entrance into said base; but if the pin is on the follower it engages the tooth of
the gear wheel at the root of the latter and moves outward along the sides of the
teeth with a receding action. This line contact is due to the fact that the side
surfaces and hence the tooth form and the interdental spaces are the result of the
development of the movement of the pin entirely across the face of the tooth.
When each pin is cylindrical any surface generated by the motion of the surface
of the pin must be either a plane, or a surface which may be considered as a bent
plane; according as the motion of the axis of the pin is in a right line or in a curve;"
and it follows that the side surfaces of the teeth of the gear are bent
planes whereon the pins always bear with line contact. The axis of the pin, in a
pair of my gears, upon analysis, will be found to describe upon the teeth of the
wheel a regular curve which, if the gears are at right angles, is a cycloid, but which
at all other angles appears to be an unnamed curve, intermediate between a cycloid
and an epicycloid. The rotation of the gear wheel, however, in combination with
the movements of the pin generates still another curvature of the side surfaces of
the teeth which warps or twists the plane, bent into the curve above mentioned,
from the front edge of the teeth to the base line thereof, and through an angle whose
arc is subtended by two planes, both including the axis of the wheel, one passing
through the front edge and the other passing through the side base line of the tooth.
In this statement, the side base line is considered as the line which is the last line of
contact of the pin with the tooth and nearest to the base thereof. Each tooth is
symmetrical with reference to the medial plane above described. In short, the side
surfaces of each tooth in my device are generated by a body circular in cross section
(whether cylindrical, conical or otherwise) whose plane of rotation is at an angle to
the plane of rotation of the revolving toothed wheel.
When the pins are cylindrical the side surfaces of the teeth are cycloidal or have
curvatures intermediate between cycloids and epicycloids, in planes perpendicular
to the axes of the pins, and these curves in fact deviate from true cycloids on
epicycloids to an extent related to and dependent upon the thickness of the pin; the
mathematical axis only of the pin, can describe a true cycloid or epicycloid or a true
curve of the intermediate form above described. Any transverse planes parallel to
the axes of the pins, or side surfaces of the teeth are straight lines and form angles
which vary from the front edge to the base or root of the tooth.
The result of the use of the form of tooth generated by the movement of the pins,
cylindrical or otherwise, on the rotary support or disk is that thereby I produce the
least possible angularity of face of the teeth, and by this form, aided if desired by
the use of an anti-friction roller, I avoid thrust to the greatest degree.
The pitch
of the teeth on the gear wheel being also the development of the rotation of the pin
gear results in close meshing of the pins and the teeth and a minimum of back lash
for free working gears.
It also follows that with a single pin gear a number of interchangeable toothed
wheels may be used, having different numbers of teeth. While there is a minimum
limit for the number of teeth which may be practically employed on a toothed wheel
gearing with a pin wheel, wheels of any number of teeth above said minimum may
be used with the same pin gear. Thus different ratios of angle gears can be
obtained by change of one member only of a pair.
The interdental spaces are cut entirely across the periphery of the wheel the
centers of the pins passing nearly through these interdental spaces, and since said

page_text: pins fit said spaces closely at and near the roots of the teeth, dirt and objects
entangled in said spaces are pushed out. Further, the driving strains are exerted
principally by or on the teeth of the gear wheel and at and near their bases, thus
bringing the driving strain nearer the bearings and lessening a tendency to bend
or buckle the wheel.
The line bearing of the pins upon the faces of the teeth tends to produce long
life of the parts and the minimum of wear, which result may be aided by the use
of anti-friction rollers. The pin does not for an instant lose an ample bearing on
the teeth and has line contact therewith throughout its roll or passage across the
same. The length of this line of contact at any instant depends only upon the
length of the tooth and the amount of the tooth allowed to extend outside the pitch
circle of the gear wheel. Hence the pin gear does not require delicate end adjust-
ment as to the length of the contact line between its pins and the teeth with which
they engage; and further the pin gear may be shifted longitudinally on its axis
and with reference to the axis of the tooth gear wheel without losing efficient
contact and as long as there is some contact possible between the pins and side
surfaces of the teeth of the wheel, the mechanism remains operative.
Dated the 15th day of January 1898.
PHILIP M. JUSTICE,
Chartered l'atent Agent, London, For the Applicant.
Angle bearing
A communication from James Henry Sager, of 7, Lake View Park, in the City of
Rochester, in the State of New York, one of the United States of America,
Manufacturer.
I, PHILIP MIDDLETON JUSTICE, of 55 and 56, Chancery Lane, London, in the County
of Middlesex, Chartered Patent Agent, do hereby declare the nature of this inven-
tion and in what manner the same is to be performed, as communicated to me by
my foreign correspondent, to be particularly described and ascertained in and by the
following statement;
-
This invention relates to angle gearing, and consists in the mechanism and
arrangement of parts hereinafter set forth. The object of the invention is to
provide an angle gearing having certain advantages due to its construction as
hereinafter described.
In the drawings:-
Fig. 1, is a front elevation of a pair of gears embodying my invention, having
axes at right angles and having twenty-four teeth in the larger member;
Fig. 2 is a transverse section on the line 2-2 of Fig. 1;
Fig. 3, is a section on the line 3-3 of Fig. 2, a portion only of the larger gear
being shown;
Fig. 4, is a front elevation of a pair of my gears with axes set at an obtuse angle
and having thirty-two teeth in the larger member, the smaller member being the
same as shown in Fig. 1;
Fig. 5, is a section on the line 5-5 of Fig. 4;
Fig. 6, is a section on the line 6-6 of Fig. 5, a portion only of the larger gear
being shown, and showing the parts in different positions from those shown
in Fig. 3;
A
Fig. 7, is an enlarged side elevation of a single tooth of the larger gear shown

page_text: Fig. 8, is an end view of the same tooth shown in Fig. 7;
Figs. 9 to 12, are sections taken respectively on the lines 9-9, 10-10, 11-11,
and 12-12 of Fig. 7;
Figs. 13 and 14 are each an enlarged elevation of a portion of the edge of the
larger gear and a portion of the pin disk with the pins thereon, the parts being
shown in positions corresponding to Figs. 3 and 6;
Fig. 15, is a partial view of a pair of my gears showing a modification; and
Figs. 16 and 17, are diagrams illustrating the action of the gear.
I have produced the gear hereinafter set forth in order to avoid many of the
difficulties found in prior angle gears and to produce an easy running and efficient
mechanism, and I accomplish this result by the mechanism now to be described.
In the drawings A is a wheel carried by a suitable shaft A¹ which, of course, is
set in proper bearings. B is a pin face gear, carried by a suitable shaft B', which
turns in proper bearings. The shafts A and B' may be set at various angles,
acute or obtuse, or at right angles to each other. In Figs. 1 and 2 the shafts are
set at right angles, while in Figs. 4 and 5 the shafts are set at an angle of about 80°.
The member B of a pair of my gears consists, as herein shown, of a disk 60 set
transversely upon the shaft B¹ and having upon said disk a series of equidistant pin
teeth b, arranged in a circle around the center of revolution of the disk, with their
axes projecting from said disk. I prefer to use cylindrical pins whose axes are
at right angles to the face of the disk and therefore are parallel to the axis of the
shaft B', but it is highly preferable and perhaps essential that each pin should have
no diameter of its working portion smaller-than that of the working portion of the
pin nearest its outer end. These pins may be solid, or, as shown in some of the
drawings, may consist of rollers b¹ set upon central pins 62. The roller b¹ may be
hardened and may revolve upon the pin 6, while the pin itself may be of softer
and tougher material. The pin is rigidly fixed to the disk in any suitable manner.
For easy construction, as shown in Fig. 5, the pin 62 is set into the disk 60 and is
fixed thereon by means of a set screw 620 extending into the pin from the back of
the disk and in order to retain the roller 6' upon the pin the outer end of the pin has
a flange 62 which overlaps the outer end of the roller and retains it between the flange
and the disk. Another arrangement is shown in Fig. 2, in which the pin is merely
screwed into the disk. If one of the hardened rollers b¹ should be cracked, worn,
or otherwise damaged a new roller may be placed upon the pin b²; and in case the
gear should be subjected to severe shock in use, the roller would crack, but the
tougher pin 6 would bend rather than break and thus insure greater safety in the
use of the device. As above stated, I prefer the use of the hardened rollars b¹
upon softer pins 62, but my device is practicable, and, under some circumstances,
is better if the whole pin b is solid.
The wheel A bears a series of equidistant teeth a for engagement with the pins b
and of the same pitch as the pins. These teeth may be set either upon the face of
the wheel A, as shown in Fig. 15, or they may be formed upon the periphery of
the wheel as shown in the other figures. When the teeth are formed upon the
periphery of the wheel the mechanism occupies less space than when the teeth are
on the face of the wheel. The teeth a are of a modified wedge shape having the
medial plane of each tooth transverse to or across the plane of rotation of the wheel,
and the apex of the wedge (whether truncated or not) points or is directed trans-
versely to said plane. When the teeth are not skew teeth, nor the wheel a skew
wheel, the medial plane of each tooth is perpendicular to the plane of rotation of
the wheel. The interdental spaces a¹ at the base lines a° of the teeth have sides
which are not radial as to the wheel but which are at said base lines parallel to each
other, and are separated by a distance only slightly greater than the diameter of
the cylinder b. This difference in width between the teeth is for the purpose of
permitting clearance of the pins without binding in the interdental spaces. The
contour of the side faces of the teeth a and the pitch are generated by the moving
pins upon the revolving disk 60 when the velocity of the gear wheel on the tooth
circle equals the speed of rotation of the circle in which the bases of the pins are
b

page_text: set, in other words, when the two members of the gear have a uniform ratio of
velocity. The contour of the side faces of the teeth and the pitch of said teeth,
will vary according to the size of the two members of the gear and of the pins upon
the member bearing them and upon the angle at which the two members are set,
as the case may be. The side surfaces of the teeth a, as shown best in Figs. 4 to 9,
are warped or twisted surfaces, upon which the pin b, if on the driving member,
has always a line contact from the position of the first engagement at the entrance
into the interdental space, with an approaching action, to the root or base of the
tooth at the position of deepest entrance into said space; but if the pin gear is the
follower, the pin engages a tooth at the root of the latter and moves outward along
the side of the tooth with a receding action. Figs. 16 and 17 illustrate respec-
tively the approaching and receding action. This line contact is due to the fact
that the side surface and hence the tooth form and interdental spaces, are the
result of being formed as if generated by the movement of the pin entirely across
the face of the tooth.
Inasmuch as, in the embodiment of my invention herein shown, each pin is
cylindrical, any surface generated by the motion of the surface of the pin must be
either a plane, or a surface which may be considered as a bent plane, according as the
motion of the axis of the pin is in a right line or in a curve; and it follows that the
side surfaces of the teeth of the gear are bent planes whereon the pins always bear
with line contact. The axis of the pin in a pair of my gears, upon analysis, will
be found to describe, upon a tooth of the wheel, a regular curve which, if the gears
run at right angles, is a cycloid but which at all other angles appears to be an
unnamed curve intermediate between a cycloid and an epicycloid. The rotation of
the wheel A, however, in combination with the movement of the pin generates still
another curvature of the side surface of the tooth, which warps or twists the plane,
bent into the curve above mentioned, from the front edge line a¹0 of the tooth to
the base line aº thereof, and through an angle whose arc is subtended by two planes,
one passing through the front edge a¹0 and the other passing through the side base
line of the tooth. In this statement the side base line is considered as the line which
is the last line of contact of the pin with the tooth and nearest to the base of the
tooth.
Each tooth is symmetrical with reference to the medial plane 1–1,
Figs. 8, 9 and 10.
In short, the side surfaces of each tooth in my device are generated by a body
circular in cross section (whether cylindrical, conical, or otherwise), whose plane of
rotation is at an angle to the plane of rotation of the revolving toothed wheel.
As illustrated in Figs. 9 and 10, when the pins are cylindrical, the side surfaces
of the teeth are cycloidal or have curvatures intermediate between cycloids and
epicycloids, in planes perpendicular to the axes of the pins, but these curves, in
fact, deviate from true cycloids or epicycloids to an extent related to and dependent
upon the thickness of the pin; the mathematical axis only of the pin can describe
a true cycloid or epicycloid, or a true curve of the intermediate form above des-
cribed. In transverse planes parallel to the axes of the pins, the side surfaces of
the teeth are composed of straight lines which on the two sides of a tooth form
angles varying from the front edge to the base or root of the tooth, as shown
in Figs. 11 and 12.
The result of the use of the form of tooth generated by the movement of the pins,
cylindrical or otherwise, on the rotary support or disk is that thereby I provide the
lowest possible angularity of face of the tooth, and by this form, aided, if desired,
by the use of an anti-friction roller, I avoid thrust to the greatest degree. The
pitch of the teeth on the wheel A, being also generated by the rotation of the pin
gear, results in close meshing of the pins and the teeth, and the minimum of back
lash for free working gears.
It also follows that with a single pin gear a number of interchangeable wheels A
may be used having different numbers of teeth. In Figs. 1 and 4 an identical pin
gear is shown meshing with wheels having 24 and 32 teeth. While there is a

page_text: -minimum limit for the number of teeth which may be practically.employed on a
toothed wheel gearing with a pin gear, wheels of any number of teeth above said
minimum may be used with the same pin gear. Thus different ratios of angular
gears can be obtained by change of one member only of the pair, while at the same
time preserving accurate and close meshing.
In the forms and proportions of teeth and pins shown in the drawings, some
under cut is provided in order to prevent binding of the pin between two adjacent
teeth when near the bases of the teeth. This under cut is shown in Figs. 7 and 12
at a², but it is limited in extent and does not prevent a sufficient and efficient line
contact between the pin and tooth for driving purposes, while preserving a close
meshing between the two members of the gear.
It is found in practice that my gear is operative even when the shafts of the two
members of the gear are not set exactly at the angle at which they were intended
to be set, and that a slight deviation from the true angle does not prevent effective
operation.
As shown in the drawings, the interdental spaces are cut entirely across the
periphery of the wheel and the centers of the pins pass nearly through the inter-
dental spaces, and since the pins fit said spaces closely at and near the roots of the
teeth, dirt and objects entangled in said spaces are pushed out. It will be seen
from Figs. 3 and 6 that, in the form of my device shown therein, the driving strains
are exerted principally by or on the teeth a at and near their bases, thus bringing
the driving strains nearer the bearings and lessening the tendency to bend or
buckle the wheel A.
The line bearing of the pins upon the faces of the teeth tends to produce long life
of the parts and the minimum of wear, which result may be aided by the use of
the anti-friction roller b¹. The roller or pin, when in operative position, does not
for an instant lose an ample bearing on the tooth and has line contact throughout
its roll, or passage across the same. The length of this line of contact at any
instant depends only upon the length of the tooth and the amount of the tooth
allowed to extend outside the pitch circle of the gear wheel.
Hence the pin gear
does not require delicate end adjustment as to the length of the contact line between
its pins and the teeth with which they engage; and further, the pin gear may be
shifted longitudinally on its axis, and with reference to the axis of the toothed gear
wheel without losing efficient contact, and as long as there is some contact possible
between the pins and the teeth of the wheel the mechanism remains operative.
The working faces of the teeth of the gear wheel and the interdental spaces have
warped limiting surfaces whose curvatures are those generated by the moving pins
when the pin gear and gear wheel revolve together; and it is clear that this con-
struction involves line contact and close meshing as between one of my gear wheels
and its pin gear, and the various adjustabilities and results herein mentioned.
I wish it to be understood that I do not intend to limit my claims to any greater
extent than the state of the art and a broad construction of their terms may require.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, declare that what
I claim is:-
1. In angle gearing, a pin gear having pins with parallel axes, in combination
with a gear wheel having an axis at an angle to that of the pin gear and provided
with interdental spaces and with teeth whose working faces have warped limiting
surfaces whose positions and curvatures are those generated by the surface lines of
the moving pins when the pin gear and gear wheel revolve together, whereby the
contact between the pins and the teeth of the gear wheel is line contact.
2. In angle gearing, a pin gear having a series of cylindrical pins having
parallel axes arranged in a circle about the axis of rotation of said pin gear and
'parallel thereto, in combination with a gear wheel having an axis at an angle to
that of the pin gear and provided with interdental spaces and with teeth whose
working faces. have, warped limiting surfaces whose positions and curvatures are

page_text: those generated by the surface lines of the moving pins when the pin gear and gear
wheel revolve together, whereby the contact between the pins and the teeth of the
gear wheel is line contact.
3. In angle gearing, a face pin gear having pins with parallel axes, in combina-
tion with a gear wheel having an axis at an angle to that of the pin gear and
provided with interdental spaces and with peripheral teeth whose working faces are
warped surfaces generated by the surface lines of the moving pins when the pin
gear and gear wheel revolve together, and the pins of said pin gear cross the
periphery of the gear wheel, whereby the contact between the pins and the teeth of
the gear is line contact.
4. In angle gearing, a face gear having a series of parallel cylindrical pins, in
combination with a gear wheel having an axis set at an angle to that of the pin
gear and provided with wedge-like teeth set transverse to the plane of rotation of
the gear wheel, and whose working faces are warped surfaces which are curved in
planes perpendicular to the axes of the pins when in contact therewith, and which
are straight lines in planes parallel to the axes of the pins when in contact there-
with.
5. In angle gearing, a face gear, having a series of parallel cylindrical pins, in
combination with a gear wheel having an axis set at an angle to that of the pin gear
and provided with peripheral wedge-like teeth, set transverse to the plane of
rotation of the gear wheel, and whose working faces are warped surfaces which are
curved in planes perpendicular to the axes of the pins when in contact therewith,
and which are straight lines in planes parallel to the axes of the pins when in
contact therewith, and anti-friction rollers on said pins.
6. In angle gearing, a face gear, having a series of parallel cylindrical pins, in
combination with a gear wheel having an axis set at an angle to that of the pin
gear and provided with peripheral wedge-like teeth set transverse to the plane of
rotation of the gear wheel, and whose working faces are warped surfaces which are
curved in planes perpendicular to the axes of the pins when in contact therewith,
and which are straight lines in planes parallel to the axes of the pins when in
contact therewith, and having the axes of the pin gear and gear wheel set to cause
the pins to cross the periphery of the wheel, and anti-friction rollers on said pins.
Dated this 29th day of March 1898.
PHILIP M. JUSTICE.