Improvements in and relating to Variable Speed Gearing.
Year: 1896

page_text: Date of Application, 4th Aug., 1896
Complete Specification Left, 22nd Apr., 1897-Accepted, 22nd May, 1897
PROVISIONAL SPECIFICATION.
Improvements in and relating to Variable Speed Gearing.
We, DAVID NOBLE BERTRAM, of the Firm of Bertrams Limited, Engineers,
St. Katherine's Works, Sciennes, in the City and County of Edinburgh, and
SAMUEL MILNE, Engineer, to said Firm, do hereby declare the nature of my
invention to be as follows:-
. This invention has reference to improvements in and relating to variable speed
gearing, and has for its object the simplifying of changing the speeds of the
machine to which it is applied, the gearing being specially suitable for paper
making machines.
As applied in connection with a paper making machine the improvements consist
in mounting a triple pinion on the steam engine or other motor shaft said pinion
consisting of three pinions of different sizes, all cast in one piece. This is mounted
on feathers sunk in the shaft, in such a manner that it can be easily slid along the
shaft and securely fixed in any desired position, but the feather would preferably
consist of a quick tapered key secured by gland being fixed to the shaft, and the
small end of it would be made circular in form and screwed the same as a cotter in
the butt end of a connecting rod.
On the main driving shaft of the machine, are keyed three spur wheels of sizes to
correspond with the three parts of the pinion. The smallest wheel and largest,
pinion being in the centre. The wheels are placed rather more than the width of
the teeth apart, while the three pinions are close together. This allows the pinion
to, be completely clear of the one wheel before engaging with the other. By moving
the pinion along the shaft it can be made to engage with either of the three wheels,
thus giving the desired changes of speed.
The advantages of this arrangement are:-
First. All the changes can be made without removing a wheel from its shaft.
Second. The wheels and pinions are placed on their shafts between bearings and
not overhung as is usual.
Third. No two pairs of wheels can possibly be in gear at the same time, thus
preventing accidents.
Fourth. The pinion being solid, and always at work cannot chew the feathers of
shaft.
Dated the 1st day of August 1896
COMPLETE SPECIFICATION.
Improvements in and relating to Variable Speed Gearing.
We, DAVID NOBLE BERTRAM, of the Firm of Bertrams Limited, Engineers,
St. Katherine's Works, Sciennes, in the City and County of Edinburgh, and
SAMUEL MILNE, Engineer to said Firm, do hereby declare the nature of our
invention and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement, that is to say :-
This invention has reference to improvements in and relating to variable speed

page_text: gearing, and has for its object the simplifying of changing the speeds of the
machine to which it is applied, the gearing being specially suitable for paper
making machines.
And in order that our said invention and the manner of carrying same into
practice may be properly understood we have hereunto appeuded an explanatory
drawing representing a plan view illustrating our improvements.
Referring to said drawing:-
As applied in connection with a paper making machine the improvements consist
in mounting a triple pinion on the steam engine or other motor shaft a said pinion
consisting of three pinions al a² a³ of different sizes all cast in one piece. This is
mounted on a feather a sunk in the shaft, in such a manner that it can be easily
slid along the shaft and securely fixed in any desired position by any suitable
means such as the quick tapered key a" which is provided with a head made
suitable for easy withdrawal when it is desired to shift the triple pinion.
On the main driving shaft A of the machine, are keyed three spur wheels A¹ A* A*
of sizes to correspond with the three parts a¹ a² as of the pinion, the smallest wheel A²
and largest pinion a' being in the centre. The wheels are placed rather more than
the width of the teeth apart, while the three pinions are close together. This allows
the pinion to be completely clear of the one wheel before engaging with the other.
By moving the pinion along the shaft it can be made to engage with either of the
three wheels, thus giving the desired changes of speed.
The advantages of this arrangement are:-
First. All the changes can be made.without removing a wheel from its shaft.
Second. The wheels and pinions are placed on their shafts between bearings and
not overhung as is usual.
Third. No two pairs of wheels can possibly be in gear at the same time, thus
preventing accidents.
Fourth. The pinion being solid, and always at work cannot chew the feathers of
shaft.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
In variable speed gearing, forming the three pinions in one casting, and mounting
same and the three corresponding wheels in such a manner that no two pairs can be
in gear at the same time, substantially as herein described in reference to and shown
in the accompanying drawing.
Dated the 21st day of April 1897.
W. R. M. THOMSON & Co.,
96 Buchanan Street, Glasgow, Agents.