Improvements in Removable Toothed Gear or Cog Wheels.
Year: 1891

page_text: Date of Application, 8th Apr., 1891-Accepted, 9th May, 1891
COMPLETE SPECIFICATION.
Improvements in Removable Toothed Gear or Cog Wheels.
I, ROBERT DUNLAP NUTTALL of Allegheny, Allegheny County, State of
Pennsylvania, United States of America, Manufacturer 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 has relation to removable-toothed gear or cog wheels, and more
particularly to gearing designed for use on electric cars and the employment of non-
metallic teeth. But the wheels may be used for other purposes than electric car
works, and metallic teeth may be substituted for non-metallic teeth, wherever the
wheels are used.
My invention contemplates the employment of an iron core and the attachment
of the teeth to the said core in such a manner that they may be readily inserted,
firmly held and expeditiously removed, the construction permitting of the removal
and replacement of the teeth without unkeying the core from the shaft.
My invention consists of a gear wheel composed of an iron or other metallic
core, having peripheral open sided sockets, with removable teeth, and a clamping
ring or rings interlocking with the edges of the teeth, and securing the same from
lateral and radial displacement.
In the accompanying drawings illustrating my invention, Figure 1 is a broken
section of a wheel inside elevation, with part of the clamping ring broken away.
Figure 2 is a radial section of the same, on the plane of the face of one of the
teeth.
The iron core of the wheel is represented as consisting of the toothed circle 1,
hub 2, and connecting web 3. Or in the place of the continuous web 3, shown,
spokes may be substituted. The periphery of the tooth circle has open sided kerfs
or sockets a, a, formed therein, either by casting or milling. The sockets or kerfs
are separated from each other by partitions b, h.
In said sockets a, a, are received the removable teeth, which may be of varying
proportions and form according to the material of which the teeth are made, the
In the
work required, and the contour of the clamping rings hercafter described.
drawing I show a tooth whose stem flares outwardly on its edges from the crown: to
the bottom, thus producing a dovetail enlargement of the base of the tooth, while
the sides of the tooth stem, flare outward from the bottom to the crown, being thus
wedge shaped to correspond with the converging sides of the tooth sockets or
kerfs. c. c. designate the crown portions of the teeth. The sides of the core are
made beveled to correspond with the flare or dovetail enlargement of the stems of
the teeth and are flush with the edges thereof. 4. 4. are duplicate clamping rings,
which are beveled, dished or depressed on their inner surfaces to fit snugly against
the beveled surfaces of the edges of the teeth, and are secured to the core by
Non-metallic
transverse bolts d, d, passing through said clamping rings and core.
teeth may be made from different woods, fibre, raw hide etc.
The teeth should be made of a size slightly greater than the size of the socket,
so that the clamping rings may grip them firmly, and in the case of non-metallic
teeth, compress them tightly in their sockets.
The non-metallic teeth before being driven in, are preferably coated with white
lead, shellac or other common filler.
When the crowns of the teeth are either broken down or worn off, the stems may
be easily removed without disturbing the core by unbolting the clamping rings and
forcing the stems out through the sides of the sockets or kerfs. The iron core,
which gives solidity to the structure, remains upon the axle as a fixture.
Obviously, one of the clamping rings may be made integral with the core.

page_text: :.
An essential feature of the construction above described is, that the teeth are
held in place by the clamping rings, the teeth and clamping rings being interlocked
by a projection or enlargement on one, fitting, a corresponding depression in the
other, thus, as shown in the drawing, the teeth have stems which project outwardly
and into the depressed or dished clamping rings, so that the teeth are prevented
from being accidentally displaced either laterally or radially..
Having now particularly described and explained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
**
First gear wheel, consisting of a core, having peripheral open sided Kerfs
or sockets, containing laterally removable teeth, a removable clamping ring secured
to said core, and abutting against the edge of the socketed portion of each tooth,
the tooth and clamping ring being formed, the one with a projecting portion and
the other with a corresponding depressed portion, whereby the teeth and clamping
ring are interlocked, and the teeth secured against radial and lateral displacenient,
substantially as shown and described.
Secondly-In a gear wheel, the combination with a core, having peripheral
open sided kerfs and laterally removable teeth with widened bases of dished or
depressed clamping rings secured to the core and embracing the bases of said teeth,
substantially as shown and described.
Thirdly gear wheel consisting of a core having open sided peripheral kerfs
or sockets, with removable teeth and a clamping ring or rings interlocking with the
edges of said teeth, and securing the same from lateral and radial displacement
.substantially as shown and described.
Dated this 8th day of April 1891
ROBERT DUNLAP NUTTALL.
By Henry Skerrett,
6, Livery Street, Birmingham, Agent for Applicant.