IMPROVEMENTS IN TOOTH-GEARING
Year: 1880

page_text: LETTERS PATENT to Herbert John Haddan, of the Firm of Herbert and
Company, Solicitors of Patents, of 67, Strand, in the City of Westminster,
Civil Engineer, for an Invention of "IMPROVEMENTS IN TOOTH-GEARING."
A communication from abroad by Delcey-Petit, of Richebourg, in the Republic
of France.
PROVISIONAL SPECIFICATION left by the said Herbert John Haddan at the
Office of the Commissioners of Patents on the 6th December 1880.
HERBERT JOHN HADDAN, of the Firm of Herbert and Company, Solicitors of
Patents, of 67, Strand, in the City of Westminster, Civil Engineer. "IMPROVEMENTS
IN TOOTH-GEARING." A communication from abroad by Delcey-Petit, of Richebourg,
in the Republic of France.
This Invention relates to mechanism for transmitting motion in a manner similar
to that of an endless screw and worm wheel, and has for its principal object to
reduce the friction between the teeth.
The teeth of the wheel which corresponds to the ordinary worm wheel form
helical surfaces and engage with a pair of friction rollers mounted opposite each
other on a shaft which corresponds to the shaft of the endless screw. The outside.
of the tooth wheel has the shape of a grooved ring (produced by the revolution of
a circle or part of a circle round an axis placed outside the circle, but in the
same plane with the latter), the inside of which grove is beset with belical teeth;
and in order to introduce the shaft with its friction rollers into the groove of the
wheel the annular groove is open at the circumference. The blanks between the
teeth are broader at the base than at the top of the latter, and the friction rollers*
which run between the teeth are truncated cones revolving on conical pins screwed
or otherwise secured to their shaft, the latter having at this place an oval or
elliptical collar, through the major axis of which pass the said conical pins which
carry at their extremities the revolving friction rollers.
This kind of gearing is especially intended for thrashing machines, but may be
applied for a great many other purposes.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Herbert John Haddan in the Great Seal Patent Office on the
31st May 1881.
HERBERT JOHN HADDAN, of the Firm of Herbert and Company, Solicitors of
Patents, of 67, Strand, in the City of Westminster, Civil Engineer. "IMPROVEMENTS
IN TOOTH-GEARING." A communication from abroad by Delcey-Petit, of Richebourg,
in the Republic of France.
This Invention relates to mechanism for transmitting motion in a manner similar
to that of an endless screw and worm wheel, and has for its principal object to
reduce the friction between the teeth. The teeth of the wheel which corresponds
with the ordinary worm wheel form helical surfaces and engage with a pair of
friction rollers mounted opposite each other on a shaft which corresponds to the shaft
of the endless screw. The outside of the tooth wheel has the shape of a grooved
ring (produced by the revolution of a circle or part of a circle round an axis placed
outside the circle but in the same plane with the latter), the inside of which groove is
beset with helical teeth; and in order to introduce the shaft with its friction
rollers into the groove of the wheel the annular groove is open at the circum-
ference. The blanks between the teeth are broader at the base than at the top of
the latter, and the friction-rollers which run between the teeth are truncated cones
revolving on conical pins screwed or otherwise secured to their shaft, the latter
having at this place an oval or elliptical collar, through the major axis of which
pass the said conical pins, which carry at their extremities the revolving friction-
rollers. This kind of gearing is especially intended for thrashing machines, but
may be applied for a great many other purposes. The accompanying Drawing will
serve to illustrate a convenient and practical mode of performing the Invention,
Figure 1 being a side elevation; Figure 2, enlarged section of the rim of the wheel;
Figure 3, section; and Figure 4, side view of the shaft. Like letters denote like
parts. M, the wheel; K, the worm or threads thereof; E, the shaft; O, H, opening for
introduction of shaft; D, friction rollers; V, screws on which D revolve; R, collar
or camb. From what has been said above the improvements will be readily
understood.
In witness whereof, I, the said Herbert John Haddan, have hereunto set my
hand and seal, this Twenty seventh day of May, A.D. 1881.