Gauges and the like.
Year: 1888

page_text: Date of Application, 16th Mar., 1888
Specification Accepted, 4th May, 1888
Gauges and the like.
I, EDWIN ALFRED HOAD, of "Claremont," Wellesley Road, Gunnersbury, in the
County of Middlesex, 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:-
This invention relates to apparatus for testing pressure and vacuum gauges, and
the liko.
The said invention is designed to improve the construction and increase the
efficiency of apparatus of this kind or class wherein the pressure or vacuum is obtained
by means of a piston or plunger working in a cylinder having ports or passages which
communicate with a check-gauge and with the gauge or gauges to be tested.
In the accompanying drawings
Figure 1 is a plan, and
Figure 2 a side elevation, partly in vertical central section, of the improved gauge-
testing apparatus.
Figure 3 is a side elevation showing part of a casting comprising a cylinder and
other parts as hereinafter described.
Figure 4 is a transverse section on the line a, z, Figure 1.
Figure 5 is a plan, partly in section, showing the piston and other parts of the
apparatus detached, and
Figure 6 is an end elovation of a cap or cover hereinafter reforred to.
Figure 7 is a side elevation, and
Figure 8 an end elevation illustrating a modification of my said invention.
Figure 9 is an elevation of a lever and pawls hereinafter described.
a is the cylinder which communicates in a well-known manner with the pipes A, B
to which the gauges are to be applied. b is the piston, the rod c of which is screw-
threaded throughout its length. Upon this screw-threaded piston-rod c is fitted a
screw-nut & supported in a suitable bearing e in close proximity to the front end of
the cylinder. The nut d is formed with collars d' so that, although it is free to bo
rotated, end wise movement thereof is provented. The rotation of the nut d is effected
Price 1171

page_text: through the medium of arms or handles formed on a boss or hub g which is secured
upon the nut d by means of a set-screw g¹ or otherwise..
The bearing e and cylinder a are made in one picco so that great strength is obtained
as compared with other gauge-testers.
The screw-threaded piston-rod e is provided with a groove or keyway h, and a
removable key is passed through the bracket or support and inserted in the said
keyway. This key is held in place by a set-screw i¹. In this manner rotation of the
piston-rod with the nut d is prevented, so that, when the said nut is caused to turn,
the said rod, and with it the piston in the cylinder a, will move longitudinally in the
said cylinder.
A recess or cavity k is formed in the nut d for the purpose of enabling the piston b
to be completely withdrawn from the cylinder a by means of the said nut without
removing the bracket or hearing e. It will be seen that, when the piston has been
drawn back into the recess k, the said piston and the parts for actuating the same can
be removed by simply unfastening the cap of the bearing e and lifting them out, and
can be replaced in their proper position with equal facility.
To permit the application of considerable forco when high-pressure gauges are to
be tested, a removable lengthening rod m is provided which is placed upon the arms
or handles to increase the leverage thereof. This rod m may be of any desired
length.
At the end of the apparatus opposite to that where the devices for actuating the
piston aro situated, is arranged.a valve n for regulating or controlling the flow of
liquid through the feed-port o of the cylinder a. This valve consists of a screw-
threaded rod having a pointed or taper end which is screwed into a socket g and bears
against the seating formed in the feed-port o. A cap containing packing is screwed
upon the socket y to ensure a tight joint around the valve-stem. A small pipo s is
provided for communication between the interior of the socket 9 and a receptacle for
The liquid which is to ho introduced through the feed-port o into the cylinder.
C
To test a pressure-gaugo by means of the above described apparatus, the valve n is
opened and the nut d on the screw-threaded piston-rod c is turned by means of tho
arms or levers so as to bring the piston to the rear end of its stroke as shown in
Figure 2, and thus draw liquid into the cylinder through the port o. The valvo is
then closed and the piston is moved in the reverse direction, by reversing the motion
of the arms or handles secured to the nut d. Any desired pressure may thus be applied
to the gauges. After the testing operation has been performed, the liquid or fluid
contained in the cylinder and gauges can, if desired, be removed by opening the
valvon and allowing or causing it to flow back into the aforesaid receptacle.
If vacuum gauges are to be tested by this improved apparatus the valve n is closed
while the piston is at the forward end of its stroke next the feed-port. On moving
the piston to the rear end of the cylinder, a vacuum or partial vacuum will be created
in the gauges.
In Figures 7, 8 and 9, I have shown another modification of my invention wheroin
I employ, in place of the handles and hub above described for rotating the operating
screw-nut, a double ratchet dovico hereinafter described. This dovico comprises two
ratchet-wheels t, u; the wheel t is formed on, or firmly attached to the nut d; the
wheel u is fitted upon an extension d' of the said nut and is secured thereon by a set-
screw or in any other convenient manner; a lever vis mounted upon the said
extension d so that it is free to turn thereon. This lever has pivoted thereto two
pawls w, adapted to engage with the teeth of the ratchet-wheel t, u. The said
pawls are weighted so that they will fall into or out of engagement with the said
teeth as the case may be. The lever v can be so operated that either one or the other
of the pawls will engage with the corresponding ratchet-wheel, and the lever will turn
the nut d in one or the other direction as may be required, the teeth of the ratchet-
wheelt extending in the opposite direction to that of the teeth of the ratchet-wheel u,
as shown. By means of this device, great force may be applied to the piston b, as a
socketed handle of any desired length may be placed upon the lever v, or the said
lever made of any desired length. Moreover, as the socketod handle does not require

page_text: to be removed in operating the apparatus, the operation thereof can be very rapidly
effected.
i
The construction of my improved gauge-tester may be otherwise modified if desired
for example the screw-threaded rod c may be provented from turning by means of a
plate or bar bearing against a flat surface on the said rod, or otherwise.
By the improved gauge-tester above described very high pressures may readily be
applied to the gauges.
•
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I wish it understood that
I claim :-
First-A gauge-testing apparatus of the kind or class hereinbefore referred to,
whorein the bearing for the operating screw-nut is formed in one piece with the
cylinder.
Second A gauge-testing apparatus in which the bearing for the operating screw-
nut is in close proximity to the cylinder and is formed in one piece therewith or
firmly attached thereto, as above specified.
Third The combination, with the cylinder and piston, of the screw-threaded rod c,
means for preventing rotation of the said rod whilst permitting longitudinal or
end wise movement thereof, and the screw-nut d held in the bearing e, and provided
with means for rotating it, substantially as, and for the purpose, set forth.
Fourth-The combination, with the piston and the screw-threaded piston-rod, of a
scrow-nut provided with a recoss or cavity to receive the said piston, substantially as,
and for the purpose, set forth.
Fifth The combination of parts comprising the screw-nut d.and the boss or hub
provided with the arms or handles f, with or without the lengthening rod m, all
substantially as, and for the purposos, set forth.
Sixth The combination of parts comprising the socket g at the end of the feed-
port the valve n and the pipes, substantially as, and for the purpose, set forth.
Seventh The improved device comprising the ratchet-wheels, the lever and the
pawls pivoted to the said lover, substantially as set forth.
Eighth The improved apparatus consisting of the parts constructed and combined
substantially as described with reference to Figures 1 to 6, or modified as described
with reference to Figures 7, 8 and 9 of the accompanying drawings and operating as,
and for the purposes, specified.
Dated this 15th day of March 1888.