Improvements in Apparatus for Blowing Organs by Electric Motors.
Year: 1896

page_text: Date of Application, th Feb., 1896
Complete Specification Left, 6th Nov., 1896-Accepted, 9th Jan., 1897
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Blowing Organs by Electric Motors.
We BERNARD MERVYN DRAKE and JOHN MARSHALL GORHAM Electrical
Engineers, both of 66, Victoria Street, Westminster, S.W., do hereby declare the
nature of this invention to be as follows:-
The object of this invention is to keep the bellows constantly supplied with air
in proportion to the demand and automatically. One of the usual methods of
doing this is to drive a worm wheel by means of a worm either on the motor
spindle or on a shaft driven by the motor and to fix a crank of the worm wheel which
actuates the bellows or feeders, the regulation being effected by varying the speed
of the motor by inserting resistances, these resistances being put in or out of circuit
by the rising or falling of an arm attached to the bellows.
Varying the speed of the motor is not an economical means of reducing the
power and not only is there a great waste in the resistances but incessant sparking
at the contacts as the switch travels over them.
In our arrangement we allow the motor to run at its normal speed and we vary
the stroke of the rod or lever actuating the feeders or bellows by means of a
link motion such as is used in the reversing gear of locomotives and in some
expansion gears.
This link works on a pivot at one end and the other end oscillates the full stroke
required. It is obvious that if the motion is transmitted from this link to the
bellows the length of the stroke will depend upon the position of the pin or block
in the link which forms the end of the driving rud.
The link is suspended by suitable levers in such a way that it is raised or lowered
with the bellows."
As the bellows become full the stroke decreases and if the air is not required and
they remain full the link rises until the oscillating rod ceases to work the reverse
taking place immediately the bellows begin to empty. As the rod ceases to work
the load is automatically thrown off the motor and it is a well known fact that the
back E.M.F. cuts off the current as the load is taken off the motor running at
practically the same speed but absorbing no more power than is required to
revolve it.
Dated this 29th day of January 1896
BERNARD M. DRAKE.
J. M. GORHAM.
COMPLETE SPECIFICATION.
Improvements in Apparatus for Blowing Organs by Electric Motors.
We, BERNARD MERVYN DRAKE and JOHN MARSHALL GORHAM, Electrical,
Mechanical and Hydraulic Engineers, both of 66, Victoria Street, Westminster,
London, S. W. 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 object of this invention is to keep the bellows constantly supplied with air

page_text: in proportion to the demand and automatically. One of the usual methods of doing
this is to drive a worm wheel by means of a worm either on the motor spindle or
on a shaft driven by the motor and to fix a crank on the worm wheel which actuates
the bellows or feeders, the regulation being effected by varying the speed of the
motor by inserting resistances, these resistances being put in or out of circuit by the
rising or falling of an arm attached to the bellows.
Varying the speed of the motor is not an economical means of reducing the
power and not only is there a great waste in the resistances but incessant sparking
at the contacts as the switch travels over them. In our arrangement we allow the
motor to run at its normal speed and we vary the stroke of the rod or lever
actuating the feeders or bellows by means of a link motion such as is used in the
reversing gear of locomotives and in some expansion gears.
This link (A) works on a pivot (B) at one end and the other end (C) oscillates
the full stroke required. It is obvious that if the motion is transmitted from this
link (A) to the bellows (D) the length of the stroke will depend upon the
position of the pin or block (E) in the link which forms the end of the driving
rod (F).
The link is suspended by suitable levers (GG) in such a way that it is raised or
lowered according to the amount of air in the receiver.
As the bellows become full the stroke decreases and if the air is not required
and they remain full the link rises until the oscillating rod ceases to work, the
reverse taking place immediately the bellows begin to empty. As the rod ceases
to work the load is automatically thrown off the motor (H) and it is a well known
fact that the back E.M.F. cuts off the current as the load is taken off, the motor
running at practically the same speed but absorbing no more power than is required
to revolve it.
It is evident that the constant speed of the shunt motor may be varied by any of
the well known mechanical methods of varying the speed such as two coned pulleys
with a belt the position of which is varied by the amount of air in the receiver, or
a friction disc drawn nearer or further from the centre, or other such device.
: Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what we
claim is :-
1. The use of a link motion for blowing the bellows of an organ by which the
amount of motion imparted to the bellows depends upon the position of the link
'block.
2. The use of a link motion driven by a shunt wound electric motor by which
the current used will be automatically adjusted to the load without the use of
resistances or other equivalent current checking devices.
3. The use of a shunt wound motor running at an approximately constant speed
with a suitable mechanical means of reducing the amount of motion imparted to
the bellows.
. Dated this 6th day of November 1896.
BERNARD MERVYN DRAKE.
J. M. GORHAM.