Improvements in Crank Driving Gear.
Year: 1895

page_text: Date of Application, 6th July, 1895
Complete Specification Left, 4th Apr., 1896-Accepted, 9th May, 1896
Improvements in Crank Driving Gear.
I CHARLES JOHN ROBINSON of Railway Works, Rochdale in the County of
Lancaster, Engineer, do hereby declare the nature of this invention to be as
follows:-
The invention relates to gear for driving sieves, polishers, and other bodies or
apparatus in which each point in a horizontal plain has a circular motion around an
independent centre.
The object is to construct such gear so as to be free from vibration when in
motion.
Gear under my invention consists essentially of a vertical shaft carried in ball
bearings, and having at one end a fly wheel adjustable as regards its centre of
gravity, in combination with an adjustable or fixed excentric pin or connection for
giving motion to the sieve or other body or apparatus. The relative proportions
and positions of the various parts being such that the centres of gravity and
gyration coincide with the axis of rotation of the driving shaft at or near one point.
Dated the 5th day of July 1895.
T JOHNSON
I CHARLES JOHN ROBINSON of Railway Works Rochdale in the County of
Lancaster, 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 :-
The invention relates to gear for driving or imparting motion to sieves, purifiers,
polishers, and other bodies or appliances in which each point has a circular motion
around an independent centre in a horizontal or nearly horizontal plane.
Hitherto the driving gear used to impart motion to appliances such as above
mentioned more especially to sieves and purifiers used in the treatment of meal
and flour, has, owing to its construction produced and been subject to excessive
vibration thereby causing rapid deterioration of the machinery and injuriously
affecting the buildings, containing such machinery.
Now the object of my invention is to construct such gear so that it shall act and
give motion to the machinery practically without the production of vibration, thus
increasing the life of the parts, reducing the driving power required and enabling
such machinery to be used in buildings and under conditions where it would
otherwise be inapplicable.
Gear under my invention consists essentially of a vertical shaft carried in ball
bearings and having at one end a fly wheel adjustable as regards its centre of
gravity, in combination with an adjustable or fixed excentric pin or connection for
giving motion to the sieve or other body or apparatus. The relative proportions
and positions of the various parts being such that the centre of gyration coincide
with the axis of rotation of the driving shaft.

page_text: DESCRIPTION OF THE DRAWINGS.
The
Fig. 1 is a vertical section part being in elevation, and Fig. 2 is a horizontal
section at the line A-B looking downwards, of driving gear constructed in
accordance with my invention. a is the crank shaft. b is a driving pulley secured
to the crank shaft a at the upper end. c are pedestals secured to beams or other
suitable carriers d. The pedestals c surround the shaft a and are provided with
bearings c¹, c². a, a, are collars on the shaft a between which and the bearings c, c²,
are balls e. The lower collar a bears the whole weight of the shaft a and gear, and
rests against a fillet a³ on the shaft so that it may be renewed when worn.
upper collar a¹ screws on to the shaft a and is adjusted until it fits sufficiently close
to the balls on the upper bearing c¹ to prevent side and end motion without causing
additional friction. To the lower end of the shaft a is secured a balancing wheel f
made with a chamber f¹ at one side to receive a weight g. h is a screw passing
through a recess f in the rim f³, and also through a nut or threaded hole in the
weight 9 into a bearing f in the boss of the wheel f. h fillet, and ³ collar for
preventing end motion of the screw h. g¹ set screws for securing the weight g in
position. is a tee-shaped recess in the bottom of the wheel f having at one end
an opening . j is a crank pin provided with a head which is passed through
the opening and behind the projections of the tee shaped recess i. kuut
screwing on the pin j so as to grip the projections 2 and secure the crank-pinj in
position. bearing into which the crank pin j fits. The bearing is carried in a
bracket m, which is secured to the frame of the sieve or like appliance in the
desired position preferably central. The sieve or like frame is freely suspended
from three or four points in the usual way.
g
The weight g, and the crank piu j are adjusted to such distances from the centre
according to the weight of the sieve or like apparatus to be moved that the centre
of gyration of the moving parts of the driving gear combined with the centre of
gyration of the sieve or like appliance coincides with the axis of rotation of the
shaft a.
In this way lateral strain is not conveyed to the bearings, and vibration
is avoided.
Having now particularly described and ascertained 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. The improvements in driving gear substantially as and for the purpose set
forth.
Second. Driving gear consisting of a shaft a, balancing wheel and adjustable
weight g and crank pin j.
Third. Driving gear consisting of a shaft a, ball-bearings, balancing wheel fand
adjustable weight g and crank pin j.
Fourth. The combination of adjustable crank driving gear with sieve and like
appliances having a circular motion substantially as set forth in such manner that
the axis of rotation of the driving shaft a coincides with the combined centre of
gyration of the driving gear and sieve or like appliance.
Dated the 2nd day of April 1896.
J. JOHNSON,
Patent Office, 4 Clayton Square, Liverpool, Agent.