IMPROVEMENTS IN OR RELATING TO APPARATUS APPLICABLE FOR LAWN TENNIS POLES AND STRETCHERS PROVISIONAL SPECIFICATION
Year: 1883

page_text: LETTERS PATENT to John Mellor of Corwen in the county of Merioneth for an
Invention of "IMPROVEMENTS IN OR RELATING TO APPARATUS APPLICABLE
FOR LAWN TENNIS POLES AND STRETCHERS
PROVISIONAL SPECIFICATION left by the said John Mellor at the Office of
the Commissioners of Patents on the 17th April 1883.
JOHN MELLOR of Corwen in the county of Merioneth "IMPROVEMENTS IN OR
RELATING TO APPARATUS APPLICABLE FOR LAWN TENNIS POLES AND STRETCHERS."
Lawn tennis nets are liable to expansion and contraction according to the
weather. If when very tight a shower of rain comes, and the net be not slackened
it is liable to tear, and even in playing, the net frequently requires adjusting or
the height will alter considerably. Now my invention is designed to avoid undue
strain on the net, yet always keep it at precisely the same height and with a
uniform strain upon it; each end of the net I attach to a lath of wood or other
material of the regulation height, this can be fastened to a pole at one end or can
itself be a pole if desired.
Near the other end I plant firmly in or on the ground in any ordinary manner
a pole or davit preferably bent over at the top away from the net. This davit is
formed of two parts united with bolts, distance pieces, or washers between of
greater thickness than the pulleys, and between the two parts are axles, whose
height can be adjusted; I place pulleys two near the top and one near the level of
the ground. The cord from the bottom of the net passes round the lowest pulley,
then up and round one of the upper pulleys-then round a pulley supporting a
tension weight and then round the other upper pulley to the top of the net. The
upper surface of the upper pulley and the lower surface of the lower pulley, are
arranged at as nearly as possible the height at which the upper and lower edges of
the net are required respectively to stand, so that when the cord is in tension ou
them it shall hold the net at the required height.

page_text: The height of the pulleys on the standard is preferably regulated by piercing the
standard with numerous holes and placing the axles of the pulleys in such holes as
will allow the cord carrying the net to stand at the right height. The weight
keeps the net stretched to a practically uniform height and strain no matter what
the expansion and contraction may be. It will be obvious that the exact
arrangement of the pulleys can be varied considerably; a separate weight might be
used for the top and bottom respectively, or a spring might be substituted for one
or both weights. Weights have these advantages over a spring, however, 1" they
always pull with a uniform and constant force, 2nd they are less likely to rust,
decay, or get out of order.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Mellor in the Great Seal Patent Office on the 17th October
1883.
JOHN MELLOR of Corwen in the county of Merioneth
"IMPROVEMENTS IN OR
RELATING TO APPARATUS APPLICABLE FOR LAWN TENNIS POLES AND STRETCHERS.”
Lawn tennis nets are liable to expansion and contraction according to the
weather. If when very tight a shower of rain comes, and the net be not slackened,
it is liable to tear, and even in playing, the net frequently requires adjusting or
the height will alter considerably. Now my invention is designed to avoid undue
strain on the net, yet always keep it at precisely the same height and with a
uniform strain upon it.
It is best described by aid of the accompanying drawings representing my latest
and most improved form.
A is the net attached at each end to lath B of regulation height. This lath can
be of wood, iron, or even of rope or other inexpensive material made to regulation
height. This can be attached to the pole C at one end or form part of the said pole
if desired. To this lath the net is stretched or fastened. Near the other end of
the net, I plant firmly in or on the ground in any ordinary manner the pole or
davit D preferably bent over from the metal top. This davit as shewn is formed
of two parts united by bolts and distance thimbles, pieces, or washers placed around
the bolts between the two parts of the davit and a little thicker than tho pulleys
or sheaves hereafter described, at intervals such as the points E E E, and in bearings
between the two parts of the davits or axles whose height can be adjusted I place
pulleys or sheaves L or L', K, and J hereafter described. The davits can however
be made of simple bar iron with the pulleys or sheaves placed on the side. To
counteract the strong pull of the net, I usually sink in the ground the angle iron
foot-plates F rivetted or bolted to the poles by a bolt passing between the two
bars or a single bar affixed thereto and a washer and nut on the outside.
G is a weight suspended by a cord hooked to the eyes of the net at H and I
and passing over pulleys J, K, and L, or if a very narrow net L' the two first
mentioned pulleys being near the top of the davit and L near the level of the
ground.
The cord from the bottom of the net passes round the lowest pulley L, then up
and round the upper pulley. K, then a pulley M supporting the tension weight G,
and then round the other upper pulley J to the top of the net at H. The upper
surface of the upper pulley and the lower surface of the lower pulley are arranged
at as nearly as possible the height at which the upper and lower edges of the net
are required respectively to stand, so that when the cord is in tension on them it
shall hold the net at the required height.
The height of the pulleys on the standard is preferably regulated by piercing the
standard with numerous holes and placing the axles of the pulleys in such holes as
will allow the cord carrying the net to stand at the right height. In the drawing
extra holes are shown for the lower pulley—if the upper pulleys are to be adjusted
the shape of the davit must be altered to suit. The weight G keeps the net
stretched to a practically uniform height and strain no matter what the expansion
and contraction may be. It will be obvious that the exact arrangement of the
pulleys can be varied considerably; a separate weight might be used for the top
and bottom respectively, or a spring might be substituted for one or both weights
but have these disadvantages, first, that unless arranged with expensive com-
pensating arrangements such as the fusee or expanding cone barrel of clocks and

page_text: watches the pull is not uniform. Second, they are more liable to get out of order,
to rust and decay, and are more costly.
The advantages of these nets over others are as follows:
The nets may be left out during the season without tearing, but can be unhooked
to mow the grass.
The weight or weights (as required) keep the net always taut and at regulation
height, notwithstanding the variations of weather.
No centre support required with light nets.
Nets of any width may be used, and by merely altering the pulleys the height
can be adjusted without lifting the poles.
The poles are easily fixed, durable, rigid, and act very satisfactorily.
The following are useful instructions for use :
To allow for expansion, the poles should be placed about three feet wider apart
than the length of net.
To fix poles. With a crow-bar make holes in the ground rather obliquely from 1
the court and press them in, when the strain will draw them upright.
Pulleys can be changed to the other bearings prepared, in order to suit width or
height of net, and the davit may be lowered by raising the foot-plate.
The ropes are to be laced through the net in the usual manner, and the wood
stretchers whipped to each end, as shown in the drawing; but, should the net exceed 2
three feet in width, thread the lower rope at that distance, and allow the extra net
to fall below it. Except when bevelled nets are used which being made 3 feet 6
inches at each end and only 3 feet in the centre, can be threaded at extreme width
of net.
To throw all the strain upon the ropes, it is well to allow a light net to lie
rather loosely between the wood stretchers, or to contract the net by wetting,
before threading the dry rope; but a strong net does not require being slack.
The price I usually charge at the present time is for
Pair of poles, with weights, copper sash, cord, pulleys, swivel,
etcetera, complete
£ 8 d
250
50
3 3 0
If supplied with strong hemp rope and wood stretchers for net, extra
For apparatus complete, with suitable net
Having now described my invention and the best mode known to me of
carrying it into effect, I claim as my invention to be protected under the Letters
Patent-
1st. The method of stretching the nets of tennis courts so as to always keep them
at a uniform tension, which consists in attaching them by means of a cord
over pulleys to a weight or its mechanical equivalent, substantially as
described.
2nd. The manufacture of davits or tennis poles and their accessories substantially
as and for the purposes described.
In witness whereof I the said John Mellor bave hereunto set my hand and seal
this twenty seventh day of September in the year of our Lord one thousand
eight hundred and eighty three.
JOHN MELLOR (L.S.)