Improvements in Punkah Motors.
Year: 1891

page_text: Date of Application, 7th Aug., 1891
Complete Specification Left, 15th Mar., 1892-Accepted, 4th June, 1892
PROVISIONAL SPECIFICATION.
Improvements in Punkah Motors.
We, SAMUEL ROBERT BAILDON, of 1 Whitefriars Street, London, and JAMES
KERSHAW, of 97 Wood Street, London, Gentlemen, do hereby declare the nature
of this invention to be as follows:-
This invention relates to motors for working punkahıs, and comprises means for
giving a regular or an irregular motion to the punkahs. An important feature in
the invention consists in conserving the motive power, or reducing the distance
through which the driving-weight falls, by stopping the motor when the punkah is
moving in one direction.
It is sometimes desirable to move the punkah in an upward direction at a faster
rate than in a downward direction; and in order to effect this result, we cause the
punkah to fall by gravity and at the same time to lift up a counterweight which
acts in conjunction with the motive power when the punkah being raised.
We
may operate one or more punkahs by the same motor, and we may arrange the
same motor to give either a rapid upward and a slow downward movement, or a
slow upward and a rapid downward movement. The movement of the punkah may
take place from either or both sides of the hanging centre.
In one form of motor for producing the intermittent rapid and slow movement,
we attach the punkah pull-cord to one arm of a bent lever, the other arm of which
is furnished with an adjustable counterweight. This lever is fulcrumed on a stud
preferably fixed on the frame of the motor, and is oscillated by a crank pin working
in a slot in the lever. The crank is loose on its shaft and is provided with a paul
engaging a ratchet wheel on one of the spindles of the wheel-train, so that when
the ratchet-wheel spindle is rotated, it will rotate the crank, vibrate the bent lever,
and operate the punkah in one direction. When the spindle is stopped or moved
slowly, the crank is free to move round its shaft in the same direction as before, to
allow the punkah to move in the reverse direction.
When the wheel-train is set in motion the punkah is pulled forward by the
combined force of the motive power and the counterpoise. The punkah, in returning
to its hanging centre, falls by gravity, but its speed is checked by the weight of
the counterpoise.
The crank may be dispensed with, by fitting the paul on the bent lever and
causing it to rotate instead of to vibrate.
In a modification of our invention, the bent lever is inverted and furnished with
two counterweights, one on each arm. In this case the lever is suspended from a
stud or shaft so as to vibrate like a pendulum. Any mechanical equivalent may
be used instead of the counterweighted arm of the bent lever, the object being to
propel and retard the punkah alternately.
The motor is stopped while the punkah is falling, by any suitable ratchet, detent,
or clutch arrangement operated by the machine. Means are provided for auto-
matically releasing the ratchet or clutch at any desired time.
Dated this Seventh day of August 1891.
SAML. ROBT. BAILDON.
JAS. KERSHAW.

page_text: COMPLETE SPECIFICATION.
Improvements in Punkah Motors.
We, SAMUEL ROBERT BAILDON, of 1, "Whitefriars Street, and JAMES
KERSHAW, of 97, Wood Street, both in the City of London, Gentlemen, do hereby
declare the nature of this invention and in what manner the same is to be per-
formed to be particularly described and' ascertained in and by the following
statement:
2
This invention relates to improvements in motors for working punkahs, and has
for its object to conserve the motive power so that a given amount of energy will
retain a punkah in motion for a greater length of time than heretofore.
Our improved motor is so constructed as to move the punkah in one direction
only, the movement in the reverse direction being due to gravity and the momentum
of the punkah; the motor during such return motion remaining stationary so that
the energy is not expended.
In carrying out our invention we use a weight or spring as the motive power
which is transmitted through a suitable train of gear-wheels to a crank-shaft
connected to an oscillating pendulum, to which latter the punkah is also connected.
The crank is connected. to its shaft by ratchet mechanism in such a manner that
during one part of its rotation it is positively driven whilst during the other part
of the rotation it moves independently of its shaft by reason of the energy due to
the gravity and momentum of the pendulum and punkah.
To enable our invention to be fully understood: we will describe the same by
reference to the accompanying drawings in which,
1
Figures 1 and 2 are 'elevations at right angles to each other of a motor con-
structed according to our invention, and
Figures 3 and 4 are views of detail's drawn to an enlarged scale and hereinafter
referred to.
Figure 5 shews a slight inodification in the connection between the punkah and
the pendulum.
C
Similar letters of reference indicate corresponding parts in all the figures.
a, a indicate side frames, in which are mounted the drum ↳ carrying
b
a chain to
which a weight is suspended, and the train of wheels for communicating the motion
of, the said drum to the crank shaft c. indicates the crank which, as hereinbéföre
stated, is loosely mounted upon the shaft c, and e is an arm formed integral with
the crank d and serving as a counterbalance. is the pendulum which is con-
nected by the rod y with the crank d and by a chain or chord with a punkah i
which is suspended, in the ordinary manner. is a 'ratchet-wheel secured to the
shaft and having engaging with it a pawl upon the crank, the said ratchet-
wheel and pawl being so arranged that the crank will be driven in the direction
indicated by the arrow 1, Eigure 1. It is obvious that if no means were provided
for arresting the movement of the motor the crank would be constantly driven
through the medium' of, the ratchet and pawl and it is also obvious that if the
motor is stopped after it has moved the crank, say, to the position indicated, by the
dotted lines in Eigure 1, the crank could continue its 'movement under the pull
exerted by the gravity and momentum of the pendulum until it reached the position
indicated by the dotted lines in Figure 1, the pawl k, during sucli movement, of
the crank from the position to the position m, slipping over the teeth, of the
ratchet wheelj In order to stop the motor during this portion of each rotation of
the crank we mount upon the crank da cam n, upon the periphery of which bears
the end of a weighted arm o (the said cam n and arm o being shown detached in
Figure 3). The armi o is secured to one end of a short shaft p carried in a suitable
bearing in the frame a¹ and having secured to its other end a pawl q engaging
with a second ratchet wheel secured upon the shaft c (the pawl 7 and ratchet-
wheel being shewn detached in Figure 4,) so that the arm o and pawl q move

page_text: As
simultaneously. The cam n has formed in it a depressions which is so arranged
that, by the time the crank has reached the position indicated by the dotted lines
Figure 1, it will come beneath the end of the arm o and thus allow the latter to
drop, whereby the pawl 7 will engage with the wheel and stop the motor.
the crank & then moves, as hereinbefore stated, under the pull of the pendulum,
the part of the cam n, which is concentric with the axis thereof, moves under the
end of the arın o so that no movement is communicated to the latter until just
before the crank & reaches the position indicated by the dotted lines m when the
inclined portion of the said cam commences to act upon the arm o to lift the
same and thus also to lift the pawl 7 out of engagement with the ratchet-wheel
by the time that the arm d is in the position indicated by the dotted lines m.
Immediately the pawl is disengaged from the ratchet-wheel the motor again
acts upon the crank d through the medium of the pawl and drives the same to the
position indicated by the dotted lines when the operation hereinbefore described is
again repeated.
14
It is obvious that as the pendulum is connected to the punkah by the chain or
cord the said punkah will oscillate in the desired manner.
v is a counterpoise or spring which is connected at one end to a suitable fixed
point, for instance to the wall of the chamber in which the pendulum is placed and
at the other end to the pendulum itself. When the wheel train is set in motion the
punkah is pulled in the direction of the arrow 2 Figure 1 by the combined force
of the motor and the counterpoise v. The punkah in swinging in the reverse
direction has its speed checked by the counterpoise.
In order to positively swing the punkah in both directions we, in some cases,
find it advantageous to connect the punkah with the pendulum at both sides, and
for this purpose we employ a cord or chain w (Figure 5) which is connected to the
pendulum upon the opposite side to the cord à and is then led around pulleys x, 2
and connected to the punkah, as shewn in Figure 5.
It is obvious that our ratchet arrangement is advantageously employed in con-
nection with a water motor when it is required to economise the consumption of
the motive fluid.
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 :-
(1) A punkah-motor adapted to operate intermittently so that, after the punkah
has been moved in one direction by the motor, the said motor will remain stationary
during the movement of the punkah in the reverse direction, substantially as
described.
(2) In a punkah-motor the arrangement of ratchet mechanism whereby the
crank is alternately connected with and disconnected from the motor proper, sub-
stantially as described.
(3) The manufacture and use of the improved punkah-motor hereinbefore
described and illustrated in the accompanying drawings.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicants.