IMPROVEMENTS IN PRESSURE AND VACUUM GAUGES. SOME OF WHICH IMPROVE- APPLICABLE TO WEIGHING MACHINES AND DAMOMET
Year: 1883

page_text: LETTERS PATENT to Albert Hamilton Emery, of New York in the State of
New York, one of the United States of America for an Invention of
IMPROVEMENTS IN PRESSURE AND VACUUM GAUGES. SOME OF WHICH IMPROVE-
PROVISIONAL SPECIFICATION left by the said Albert Hamilton Emery at
the Office of the Commissioners of Patents on the 5th June 1883.
ALBERT HAMILTON EMERY of New York, in the State of New York one of the
United States of America IMPROVEMENTS IN PRESSURE AND VACUUM GAUGES,
SOME OF WHICH IMPROVEMENTS ARE APPLICABLE TO WEIGHING MACHINES AND
DYNAMOMETERS
The improved pressure or vacuum gauge is constructed with a case containing a
system of levers connected to the case and to one another by flexible plates. The
first lever of the system rests or bears upon a pressure column connected to or
resting on a flexible diaphragm hermetically secured at its outer edge to the case
either directly or to a part or parts interposed between it and the case and exposed
on its under face to the pressure or vacuum to be measured. The movement or
deflection of the levers is resisted by one or more springs and the extent of such
movement or deflection is shown by a rotary indicator connected with the last of
the series of levers by a band attached to the extremity of said lever and coiled
upon a drum on the indicator shaft. The upper surface of the diaphragm being
exposed to the atmosphere a vacuum communicating with the chamber beneath it,
causes the depression of the diaphragm under atmospheric pressure. Pressure of
steam or other fluid in the chamber beneath the diaphragm in excess of the
atmospheric pressure forces up the diaphragm. Hence a vacuum is measured by
the movement of the rotary indicator in one direction and pressure by the
movement of the indicator in the other direction, the instrument being provided
if desired with a dial marked with two sets of graduations reading in opposite
directions. A weight adjustable horizontally is applied to one of the levers to
counterbalance the weight of the levers and their inertia under motion. This
weight is mounted on an arm projecting either upward or downward from the lever
so that its horizontal distance from the supporting fulcrum will be changed by the
deflection of the lever and its counterbalancing effect thereby varied so as to
compensate for the varying resistance of the springs as the levers are moved. The
[Pmine 871

page_text: weight is adjustable vertically on its attaching arm to admit of varying the ratio
of increase or decrease of its counterbalancing effect in the changing position of
the levers as circumstances may require.
The final transmitting lever is connected to the case by a long fulcrum plate and
is constructed with an upwardly projecting heel to afford attachment for the
flexible plate which connects it with the intermediate lever at a point above the
level of the fulcrum attachment.
One or
more of the transmitting levers may be fulcrumed to the case by
compound flexible plates connected by an intermediate clamping piece or pieces
allowing limited horizontal play to the fulcrumed levers and one or more of the
said levers are stayed against horizontal motion by a flexible fixing plate or plates
attached at one end to one of the levers and at the other to either the case,
fulcrum-block, another lever or other firm part, and adjustable at one end. The
said fixing plate or plates may constitute a spring or springs to resist the pressure
on the gauge.
One of such resisting springs is mounted in the case through the medium of a
screw rod the adjustment of which, acting through the resisting spring on the free
end of the lever to which said spring is attached, permits the setting of the
indicator and the adjustment of the instrument to compensate for changes in
temperature or initial loads without opening the case.
The transmitting levers are made double constituting wide frames and are thus
adapted to receive fulcrum and transmitting plates which are made thin for
flexibility and wide for strength. The width of the lever frames and connecting
plates also adapts them to transmit their pressure in a vertical plane without lateral
or oblique strain.
A hair spring is provided to offer such resistance to the rotation of the indicator
as will serve to keep the parts taut.
In one form of the invention the gauge is constructed with a pressure chamber
permanently attached to a chamber base which is removable from the base of the
gauge and from the pressure column or a part thereof. The column preferably
formed in two parts, the lower being attached to the pressure chamber
diaphragm.
The final lever of the series is preferably mounted on a fulcrum block constructed
with two arcs around which its flexible fulcrum plate and the flexible plate which
connects it to the intermediate lever are respectively drawn, in order to keep the
fulcrum points in the same horizontal line. An adjustable stop limits the
downward movement of this lever when pressure is withdrawn stop screws aro
employed to limit the vertical movement of one or more of the intermediate
levers.
In order to adapt the invention for the purposes of a weighing machine or
dynamometer it is provided with a suspension device at its upper end and a load
attachment at its lower end, the suspension attachment being connected through
the medium of vertical rods with a pressure column acting on a diaphragm
applied beneath the chamber-base of the instrument, said chamber base being for
this purpose recessed in both its upper and lower surfaces to form two liquid
chambers communicating through a duct in the said base.
The load attaching device being applied to the case of the instrument, it will be
apparent that a load applied thereto, acting through the medium of the case and
the fulcrum of a lever mounted therein, upon a pressure column on which the said
lever rests, will apply pressure to the liquid within the connected chambers, the
said pressure being sustained by the suspension rods through the medium of the
lower pressure-column beneath the liquid chamber and the extent of the pressure
being shown by the movement of the rotary indicator produced by the movement
of the levers within the case, the movement of said levers being taken up by the
resisting springs.

page_text: SPECIFICATION in pursuance of the conditions of the Lotters Patent filed
by the said Albert Hamilton Emery in the Great Seal Patent Office on
the 4th December 1883.
ALBERT HAMILTON EMERY of New York in the State of New York one of the
United States of America "IMPROVEMENTS IN PRESSURE AND VACUUM GAUGES
SOME OF WHICH IMPROVEMENTS ARE APPLICABLE TO WEIGHING-MACHINES AND
DYNAMOMETERS "
Tho
The improved pressure or vacuum gauge is constructed with a case containing a
system of levers connected to the case and to one another by flexible plates.
first lever of the system rests or bears upon a pressure column connected to or
resting on a flexible diaphragm hermetically secured at its outer edge to the case
either directly or to a part or parts interposed between it and the case and exposed
on its under face to the pressure or vacuum to be measured. The movement or
deflection of the levers is resisted by one or more springs and the extent of such
movement or deflection is shown by a rotary indicator connected with the last of
the series of levers by a band attached to the extremity of said lever and coiled
upon a drum on the indicator shaft. The upper surface of the diaphragm being
exposed to the atmosphere a vacuum communicating with the chamber beneath it
causes the depression of the diaphragm under atmospheric pressure. Pressure of
steam or other fluid in the chamber beneath the diaphragm in excess of the
atmospheric pressure forces up the diaphragm. Hence a vacuum is measured by
the movement of the rotary indicator in one direction and pressure by the
movement of the indicator in the other direction, the instrument being provided
if desired with a dial marked with two sets of graduations reading in opposite
directions.
A weight adjustable horizontally is applied to one of the levers to counter-
balance the weight of the levers and their inertia under motion. This weight is
mounted on an arm projecting either upward or downward from the lever so that
its horizontal distance from the supporting fulcrum will be changed by the
deflection of the lever and its counterbalancing effect thereby varied so as to
compensate for the varying resistance of the springs as the levers are moved. The
weight is adjustable vertically on its attaching arm to admit of varying the ratio
of increase or decrease of its counterbalancing effect in the changing position of the
levers as circumstances may require.
The final transmitting lever is connected to the case by a long fulcrum plate and
is constructed with an upwardly projecting heel to afford attachment for the flexible
plate which connects it with the intermediate lever at a point above the level of
the fulcrum attachment.
One or more of the transmitting levers may be fulcrumed to the case by
compound flexible plates connected by an intermediate clamping piece or pieces
allowing limited horizontal play to the fulcrummed levers and one or more of the
said levers are stayed against horizontal motion by a flexible fixing plate or plates
attached at one end to one of the levers and at the other to either the case,
fulcrum-block, another lever or other firm part and adjustable at one end. The
said fixing plate or plates may constitute a spring or springs to resist the pressure
on the gauge.
One of such resisting springs is mounted in the case through the medium of a
screw rod the adjustment of which acting through the resisting spring on the free
end of the lever to which said spring is attached; permits the setting of the

page_text: indicator and the adjustment of the instrument to compensate for changes in
temperature or initial loads without opening the case.
The transmitting levers are made double, constituting wide frames and are thus
adapted to receive fulcrum and transmitting plates which are made thin for
flexibility and wide for strength. The width of the lever frames and connecting
plates also adapts them to transmit their pressure in a vertical plane without
lateral or oblique strain.
A hair spring is provided to offer such resistance to the rotation of the indicator
as will serve to keep the parts taut.
In one form of the invention the gauge is constructed with a pressure chamber
permanently attached to a chamber-base which is removable from the base of
the gauge and from the pressure column or a part thereof. The column is
preferably formed in two parts, the lower being attached to the pressure-chamber
diaphragm.
The final lever of the series is preferably mounted on a fulcrum-block constructed
with two arcs around which its flexible fulcrum plate and the flexible plate which
connects it to the intermediate lever are respectively drawn in order to keep the
fulcrum points in the same horizontal line. An adjustable stop limits the
downward movement of this lever when pressure is withdrawn. Stop screws
are employed to limit the vertical movement of one or more of the intermediate
levers.
In order to adapt the invention for the purposes of a weighing machine or
dynamometer it is provided with a suspension device at its upper end and a load
attachment at its lower end, the suspension attachment being connected through
the medium of vertical rods with a pressure column acting on a diaphragm applied
beneath the chamber-base of the instrument, said chamber base being for this
purpose recessed in both its upper and lower surfaces to form two liquid chambers
communicating through a duct in the said base. The load attaching device being
applied to the case of the instrument it will be apparent that a load applied thereto
acting through the medium of the case and the fulcrum of a lever mounted therein
upon a pressure column on which the said lever rests will apply pressure to the
liquid within the connected chambers, the said pressure being sustained by the
suspension rods through the medium of the lower pressure-column beneath the
liquid-chamber and the extent of the pressure being shown by the movement of
the rotary indicator produced by the movement of the levers within the case the
novement of said levers being taken up by the resisting springs.
And in order that the said invention may be more clearly understood and readily
carried into effect I will proceed aided by the accompanying Drawings more fully
to describe the same.
DESCRIPTION OF THE DRAWINGS
In the accompanying drawings the invention is illustrated in several figures
numbered 119 to 128 inclusive being part of a series of drawings consecutively
numbered and representing a series of connected or allied inventions some of which.
are described in other applications of mine of even date herewith.
Figure 119 is a front elevation of one form of gauge embodying the invention
to which this application relates.

page_text: Figure 125 is a detail elevation of the fulcrum and attachments of the final
transmitting lever.
Figure 126 is a front view of a dynamometer illustrating the invention.
Figure 126a. is a front elevation of part of the internal mechanism thereof
showing an axial section through the liquid pressure chamber.
Figure 127 is a side elevation partly in section as indicated by dotted lines in
Figure 126.
Figure 128 is a vertical section of a portion of the chambers in a plane at an
angle of 45 degrees to that shown in Figure 127.
Referring to Figures 119 to 121 inclusive 781 represents the cylindrical casing
provided with a dial 782 with a glazed front 783 attached in any preferred
manner.
784 is a screw plug for coupling the. gauge to any object in which is the
vacuum or pressure to be measured. The plug 784 screws against a sealing
plug 785 clamping at its periphery a diaphragm 787 which is clamped at its centre
to a column 788 by means of a screw 789 and clamping plate 790. The joint
between the screw plug 784 and the sealing plug 785 is of such form as to cause
the former to bear at or near the centre of the latter in order to produce substan-
tially uniform pressure of its annular face on all parts of the margin of the
diaphragm 787. The diaphragm will be seen to form a flexible air tight division
between the chambers 786 beneath it and the chamber 791 above, the latter being
exposed to atinospheric pressure while the chamber 786 is in communication with
the vacuum where the instrument is used as a vacuum gauge and with the
pressure to be measured if it be a pressure gauge. In the case of a vacuum gauge
the atmosphere presses down the column 788. In the case of a pressure gauge the
pressure in the chamber 780 acting in opposition to the atmosphere forces up the
column. A thin flexible plate 790a. secured by a screw clamp 789a. connects
the column 788 with a lever 791a. fulcrumed by a thin flexible plate 792 to the
fulcrum bracket 793. This bracket may be formed permanently within the casing
or attached thereto by screws 794. The clamp plates and screws for holding the
thin flexible plate 792 by its respective edges are shown at 795 the saine number
being used to indicate similar clamp plates and screws applied to other flexible
plates hereinafter referred to. The free end of the lever 791a. communicates
through a thin flexible plate 796 with a secondary lever 797 fulcrumed by a thin
plate 798 and bracket 798a. to the case 781 and connected by a long flexible
plate 799 with an upwardly projecting fulcrum bracket 800. The bracket 800 is
screwed to the heel of a lever frame 802 or may be made in one therewith and is
suspended by a flexible plate 801 clamped to an attaching bracket 801a. which
is screwed to the case 781. The bracket 800 is so constructed that the free parts
of the fulcrum plates 799 or the parts exposed to flexure reach above the lower
flexible parts of the fulcrum plates 801. This construction gives an increasing
fulcrum distance between the fulcrum plates 799 and 801 as the lever 802 rises.
This tends to hasten the rotation of the needle or indicator which is retarded by
other increasing resistances. The lever frame 802 carries a sensitive weight 803
which has a vertical adjustment on its standard 804 while the latter has horizontal
adjustment on the lever 802. By means of the horizontal adjustment the weight 803
may be made to balance the weight of the levers and by means of the vertical
adjustment it is made to exert a greater or less accelerating effect on the action of
the needle or indicator as the higher it is placed the more rapidly it approaches the
suspending fulcrum plate 801 as the lever S02 rises and thus accelerates the
movement of the indicator. These two adjustments permit the making of gauges
having substantially uniform graduations. This is assisted by the form of
the heel piece 800 as mentioned and still farther by varying the width length
and thickness of part or all of the fulcrum plates. To the extremity of the
lever frame 802 is clamped adjustably a flexible metallic strap 805 which is

page_text: coiled at its other end around a drum S06 on the shaft 806a. of the indicator 8066.
so as to rotate the said indicator when the column is moved in either direction.
The draft of the strap 805 is resisted by a hair spring 807 connected at
one end to the shaft of the indicator and at the other end to a pin 808 on one
of the brackets 808a. in which the indicator has its bearings. The brackets
808 and 808b are mounted on the lever 791º The pressure is further resisted in
either direction by a spring 809 shown by dotted lines in figure 119 and attached
adjustably at one extremity to the free end of the lever 797 by clamp 811 and
at the other end to a rod 810 which is made of metal of different expansibility
from the material of the case and is supported adjustably in the neck 781° of
said case by a screw 810* so as to be moved up or down to set the indicator as
required.
The dial may be provided with two sets of graduations reading in each direction
for indicating either pressure or vacuum. In practice it is preferred to set the
diaphragm 787 with its concave side toward the predominant pressure according
as the gauge is to be used for purposes of pressure or vacuum. The last lever 802
and its attached weight are made sufficiently heavy to counterbalance the
unbalanced portion of the weight of levers 791 and 797. The upwardly
projecting weight will be seen to offer an increasing or decreasing resistance to
the motion according as the lever to which it is attached is moved up or down
and the extent or ratio of this resistance may be regulated as required by the
horizontal or vertical adjustment of the standard and weight.
In figures 122 and 123, 821 represents the cylindrical casing, 822 the dial,
823 the glass front and 848 the frame thereof.
The
A packing 849 of leather or other suitable material is interposed between the glass
and its frame. 824 represents a base piece connected with the casing by screw-
bolts 825 and serving also to connect an annular fulcrum block 826 by which the
primary lever hereinafter described is attached to the case. The fulcrum block 826,
may if preferred be attached to the neck of the case by separate screws.
base 824 is formed with an annular flange as shown in figure 124 projecting upward
within the neck of the case in contact with the. plate 827 forming the base of a
removable pressure chamber. The pressure diaphragm 828 is secured at its outer
edge to the chamber base plate 827 and when made in annular form as in the present
illustration is secured at its inner edge to the lower part of a pressure column 830.
The outer edge of the diaphragm is clamped by a casing-ring 829, interposed
between the chamber-base 827 and a. shoulder within the case.
The pressure
chamber-base 827 has a central pressure duct 850 and is tapped as shown with
a screw thread to receive a screw plug for attaching the liquid pressure pipe.
The diaphragm of the pressure chamber may be either made annular as shown
and attached to the base of the pressure column or it may consist of a continuous
disc with the pressure column resting upon it either with or without
separate casing ring 829 interposed between the case 821 and the base 827 of the
pressure chamber. This construction adapts the entire pressure chamber consisting
of the chamber-base 827 and diaphragm 828, casing 829 and the base 830 of
the pressure column to be removed from the case. when the latter is taken
off its base 824. The pressure column 831 carries a clamping plate 832
securing thereto the lower edge of the flexible transmitting plate $33, the upper
edge of which is clamped by the block 857 and screws 858 to a lever 834
fulcrumed by a flexible plate 835 to the standard 851 of the fulcrum block 826.
The fulcrum plate 835 is attached to the lever 834 by a clamp plate 860 and
screws 858 and to the fulcrum block 851 by clamp plate 861 and screws 862. The
block 857 is fastened to the lever 834 by screws 858 and 859. The fulcrum
block 826 is of annular form encircling the pressure-column and is constructed
with a slight hub or shoulder resting within a recess in the neck of the casing 821
as shown in figures 122 and 124 to secure the said fulcrum block or bracket
against lateral motion while it is held down to the neck of the casing by bolts 825.
a

page_text: The free end of the lever 834 is connected by a thin flexible plate. 836 and
clamps 864 with a secondary double lever 837 fulcrummed to the case through the
medium of clamps 865, 866, and two thin flexible plates 838, 863 which are
connected by a rigid clamping piece 839. This attachment permits the horizontal
motion of the fulcrum attachment 383 due to the vertical movement of the lever.
The free end of the lever 837 connects by a flexible plate 840 and clamps 867 with
the upper part of a fulcrum block 841 carrying an arm 842 secured thereto by
clamping screws 868 which serve also to clamp thereto the lower end of the
suspending plate 843. The upper end of the plate 843 is clamped to the case by
plates and screws 844. To the extremity of the lever 842 a flexible transmitting-
band 845 is clamped adjustably, by a plate and screws 869. The said transmitting
band is coiled around a small drum 852 on the shaft 853 of the indicator 846.
A hair-spring 847 connected at one end to the shaft or drum of the indicator and
at the other end to the lever 837 by a slotted pin 854 resists the rotation imparted
to the indicator by an upward movement of the levers above described and serves
to keep the connections at a proper tension. The main resistance to the pressure
is by a spring 855 which is clamped at one end adjustably to the top of the
standard 851 by the slotted plates 870 and screws 871 and at the other end to the
free end of the lever 837 by clamp 856. The spring-plate 855 serves also to fix
the lever 837 against horizontal motion. For automatic adjustment to counteract
the effect of changes in temperature a rod 872 is provided of metal, either more or
less expansible than the material of the case, said rod being fixed adjustably in the
case as shown and connected by clamps 873 to a plate spring 874 which is clamped
to the lever 837 near its fulcrum end by plates 875 and screws 876. By the
vertical adjustment of the rod it may be made to increase or decrease the strain
upon the spring and to exert a strain either upward or downward as required to
bring the indicator to zero. If found necessary to compensate for changes in
temperature, the rod may be applied under the lever 837 instead of above it as
here shown. 877 is a stationary. rod rising from the standard 851 and provided
with a nut 878 which constitutes an adjustable stop to limit the descent of the
lever 842. The action of this stop is to limit the downward movement of the
lever 842 at such time that the band 845 shall not be loosed from its barrel by
the farther movement of the lever after the rotation of the indicator is stopped, by
its having reached the limit of its permitted movement. In practice it is best to
so adjust the said stop nut 878 that the lever 842 will strike it just before the
needle completes its movement so that the living force of the needle or indicator
is partially consumed by the elastic action of the lever 842, band 845, arbor 853
and needle 846. The result is that the needle strikes very gently at the limit of
its motion.
It is preferred to thread the rod 877 to its upper end and employ a second nut
above the lever to limit its upward play. The fulcrum of the said lever 842 is
preferably constructed as shown at 880 in figure 125, the flexible plate or the
metallic straps 840, 843, being secured to the said fulcrum by screws 881 and
clamp plates 879 and stretched around arcs as represented so that the fulcrum
distance will remain unchanged under a deflection of the levers. The shaft 853
of the rotary indicator runs in jewelled bearings 882, 883 which are set in
standards 884, 884° fixed to the annular fulcrum block 826, by screws 884b The
vertical motion of the lever 837 is limited by stop screws 885, 886, coming in
contact with lugs 887, 888, projecting inward from the case 821, the lugs 888
constituting the boss for the attachment of the clamp 844.
Many of the parts or details of this invention are applicable to weighing
machinery and dynamometers. When designed for this purpose the instrument
is provided with a suspension device at its upper end and a load attachment at its
lower end as illustrated in figures 126 and 127.
To adapt the invention to the purpose of a weighing machine or dynamometer
the chamber base is recessed and covered or provided with liquid pressure

page_text: diaphragms on both its upper and lower faces, the said chambers being connected
by a duct and the liquid in the lower chamber receiving pressure from a column
beneath it, which is connected by rods with the suspension device at the top of
the instrument while the load attaching device at bottom is connected to the case,
so that the weight or pressure of the load will be communicated through the
fulcrum, flexible plates and load lever to the pressure column bearing on the upper
diaphragm.
It will thus appear that a load or strain applied to the case through the medium
of suitable load-attaching devices will apply pressure to the liquid in the
communicating chambers above and below the chamber base and the extent of
this pressure will be shown by the movement of the indicator communicated
by the deflection of the lever or levers through which the pressure is transmitted,
said deflection being resisted and the pressure taken up by one or more springs.
The mode of applying these improvements in a dynamometer or weighing
machine is illustrated in figures 126, 126 127 and 128.
In these figures 001 represents a suspension-stem passing through a suspension
beam 902 both of which have limited vertical play within the case 903 and are
fixed from lateral motion therein by an annular plate 904 which is fastened at its
outer edge to the neck of the case and at its inner edge to the beam. This
beam 902 may be secured against lateral motion with reference to the case 903
by any suitable packing or other means such that there shall be very slight or no
lateral movement permitted and at the same time the small longitudinal movement
shall be but slightly resisted. A rubber or other elastic ring might be used for this
purpose, but the method here shown of securing them by flexible metallic plates
is preferable. Two rods 905 are fixed to the beam 902 and extend down
completely through the case as shown.
A load
A pair of lock-nuts 906 fix the stem 901 permanently to the beam 902.
beam 907 is fixed by nuts 908 to the rods 905 being tightly clamped against
shoulders on said rods by the action of the nuts. These beams 902, 907, and the
rods 905 which thus rigidly connect them constitute a fixed yoke which is
suspended by the stem 901. The upper beam 902 of this yoke lies wholly
within the weighing case and is attached thereto by the flexible plate 904
permitting relative vertical motion of the case to a slight extent but no horizontal
motion. The load-beam 907 thus fixed to the suspension stem, suspension beam
and connecting rod is fixed against lateral movement in the case by a thin flexible
annular plate 909 secured at its outer edge to a casing-ring 910 and at its inner
edge to the load beam 907. 911 represents a base-plate recessed on both its upper
and under surfaces to form liquid chambers, as hereinafter described. 912 are studs
screwed into the case 903 and formed with shoulders, whereby they fix rigidly to
the case the casing-ring 910 and chamber-base 911. It will now be seen that the
case 903 of the instrument is secured to the suspension-yoke at top and bottom by
the flexible plates 904 and 909 so as to prevent relative horizontal movement
between said case and yoke while permitting without appreciable resistance the
slight vertical movement of the case necessary in weighing. 913 is a load cross-
head clamped to the lower ends of the fixing studs 912 by nuts 914 and forming
an attachment for a load-stem 915 which is swivelled therein, being secured by a
nut 916 and washer 917. A pin 918 fastens the nut 916 to the washer 917 so as
to cause them to turn together as the stem swivels on the cross-head. 919, is a
stop-plate fastened by a screw 920 to the load-beam 907 and formed with a pro-
jecting flange or shoulder, as clearly shown in figure 127 to limit the upward
movement [of the case by the contact of the said shoulder with an inwardly
projecting flange or shoulder on the casing ring 910 when the instrument is relieved
of a load. 921 is a pressure-column resting through the medium of the plate 919
on the beam 907 and secured by a flexible metallic diaphragm 922 to the chamber
base 911, a tight chamber being thus formed between the base 911 and the
column 921. A column 923 and flexible diaphragm 924 cover the liquid chamber

page_text: of smaller area on the opposite side of the double chamber base 911, the two
chambers being connected by a liquid-duct 973 shown in dotted lines in figure 127
and in full lines in figure 128, so that when a load is applied to the case 903
pressure on the liquid in the lower chamber between the base 911 which is fixed
to the case and the column 921 which rests on the suspension yoke 902, 905, 907,
will be communicated through the duct to the smaller chamber above, developing a
pressure reduced in its aggregate by the proportionately smaller area of the chamber.
925 is a diaphragm ring which bears upon the outer edge of the diaphragm 924.
This separate ring may be dispensed with, the case 903 being formed to rest directly
on the diaphragm 924. 926 are clastic rings set partly in the load beam 907 and
covering the opening in the casing ring 910 around the rods 905. The said elastic
rings while covering the openings permit the slight relative motion of the parts
without friction. These rings 826 may be used in the same manner to exclude
air, dust etc. from the case 903 in machines where the liquid-chamber-piece 911 is
dispensed with, the case 903 in this instance resting directly on the ring 910.
927, figure 128, is a sealing plug closing the duct 974 through which the liquid
chambers and connecting duct 973 are filled. 975 is a transverse duct permitting
the escape of air from the chambers while they are filled with liquid. The upper
pressure column is preferably formed in two parts, the upper part 928 being
connected by a clamp 931 and a flexible transmitting-plate 932 to the load lever 933
which is fulcrumed by the flexible plate 934 and clamp plate and screw 935 to the
fulcrum block 930, the latter being secured by screws 929 to the case 903. A
weight applied to the case by the load-stem 915 depressing the chamber base 911
forces liquid up through the duct 973 into the chamber above developing pressure
upward on the column 923, 928, and load-lever 933.
From the load-lever 933 pressure is transmitted through a flexible plate 936 and
clamps 937, 938, to a secondary lever 942 fulcrumed by a compound flexible joint
formed by thin plates 939, 939* and clamp 940. 941 is a clamp which fixes the
plate 939 to the transmitting lever 942 and 941a, a clamp which fixes the
plate 939a, to the case. 943 represents a fixing and resisting-plate or plates fastened
by an adjustable clamp or clamps 944 to the fulcrum-block 930 and by a clamp 945
to the load-lever 942.
946 represents a temperature spring fastened by a clamp-plate 947 to the back
part of the secondary load-lever and to the case by a temperature and adjusting
rod 948 which is formed wholly or in part of metal more or less expansible than
that of the case in order to counteract automatically the effect of changes in
temperature as may be necessary. The rod 948 is screwed within the case as
shown in dotted lines in Figure 126 for the purpose of setting it up or down to
vary the pressure of the spring on the lever and to set the indicator hereinafter
described. 949 is a transmitting plate fastened by a clamp 950 to the secondary
lever 942 and by a clamp 952 to the fulcrum-block 951 of a transmitting lever 953
which is fastened to the said fulcrum-block by screws 954. A flexible fulcrum
plate 955 is fixed to the fulcrum-block 951 by screws 954 and 954a, and to a
fulcrum-bracket 956 by a clamp 957. The bracket 956 is fastened to a lug 986
on the case by a screw 958. The fulcrum-block 951 is connected to the case 903
either directly or through the medium of a bracket 956, by a thin flexible plate 959
attached to the said fulcrum-block by a clamp 960 and to the case 903 or
bracket 956 by a clamp-plate 961. From the lever 953 rotary motion is imparted
to the indicator 966 by a band 962 fastened to the transmitting-lever 953 by a
clamp-plate 963 and coiled on a drum 964 on the shaft 965 of the indicator 966.
The shaft 965 runs in jeweled bearings on the brackets or standards 967 and 968
screwed to the block 930. 969, is a hair-spring attached at its respective ends to
the indicator-shaft and to a pin 969a on the lever 942. The hair-spring offers a
slight resistance to the motion of the indicator and serves to keep the connections
taut. 970 is an annular dial in front of which the indicator works. 971 is a door
frame and 972 a glass fixed therein. 976 is a stud screwed in the lever 942,

page_text: constituting an adjustable stop to limit the downward motion of the transmitting
lever 953. 977 is a stud screwed in the beam 902 projecting downward and
constituting an adjustable stop to limit the upward movement of the lever 953.
The fixing-plate 909 may be fastened to the load beam 907 by packing, as shown,
or by clamping it with the stop-plate 919 and screw 920. If preferred the stop-
plate 919 may be entirely dispensed with, the pressure-column 921 resting directly
on the load-beam 907.
Elastic diaphragms may be substituted for the packing 926 so as to seal the
casing without friction.
By fixing the moving parts against lateral motion at their upper and lower ends
they are made steady in their vertical motion. By doubling the levers as shown
and permitting the connections 905 to work between them the strains are taken
centrally without any lateral pressure which would tend to produce unequal wear
and uncertainty in the action of the instrument.
If it be desired to adapt the machine for optional use either horizontally or
vertically, a counterbalancing weight must be connected with the lever 953, or
some other moving part to neutralize the action of gravity when the machine
is used vertically otherwise the indications will vary in the different positions of
the machine.
In Figure 127 the diaphragm 924 is shown annular and secured to the chamber-
base 911 and pressure-column 923 by solder. This diaphragm has been usually
made of brass. When in the annular form shown or when extending over the
whole area of the chamber it has heretofore been made of one or several corrugated
plates of sufficient strength to withstand the pressure of the liquid and by its
bending to communicate motion through various kinds of mechanism to the
indicator-needle. A preferable construction is shown in Figure 126a, where the
main pressure of the liquid from its action on the upper side of its chamber in
the base 911, is transmitted directly to the pressure-column 923, through a flat,
tempered, steel plate 924a which seals the chamber 911 on its upper side and is
combined with the said chamber and column 923 and ring 925 in such a way
that the lower end of the column 923 projects slightly below the face of the
ring 925 and thereby gives some considerable pressure on this diaphragm 924
when the machine is not loaded as by thus setting it, the diaphragm will remain
nearly flat throughout the whole loading of the machine from the least to the
greatest loads, thereby giving much less strain on the diaphragm and much more
uniform reading of the indicator than is obtained by other forms of diaphragms
or methods of setting. It will be readily seen that by making and setting the
diaphragm in this way I am able to use very thin flat tempered steel plates with
very narrow spans and adapt the machine to endure large pressure acting directly
on the pressure-column and to measure them much more accurately than machines
as heretofore made and with very great uniformity in the readings of the indicator.
To seal the chamber 911 securely without solder a sealing ring or rings 925u are
employed, usually made of soft brass put in as shown in Figure 126a which rings
must be sufficient in thickness to prevent the chamber-piece 911 from pressing
directly against the fulcrum-block 930 when secured firmly in its scat by screws
not herein shown.
In using this combination of the plate 924a and pressure column 923 the latter
must be secured very carefully against lateral motion and without friction which is
here done by means of the steel diaphragm 9246 attached to the column 923 by
the screws 923a or other suitable means. In this case the outer part of this
diaphragm is secured by the pressure between the ring 925 and the fulcrum-
block 930, produced by the screws (not here shown) which secure the chamber-
base 911 to the fulcrum-block 930.
In order that this method of making and setting the diaphragm 924a shall work
with the greatest efficiency it is necessary to so connect the pressure-column-923
with such parts that even with the largest pressure from the liquid beneath it, it

page_text: will have only very slight motion while the indicator moves throughout its whole
stroke and to provide for the accurate measuring of the pressure on this column it
is best made of one piece of steel and with connections as shown in Figure 126a
where the fulcrums 932, 934a, 936 and 939 are all of tempered steel and secured
against backlash to levers 933 and 942, 933 is a solid lever and 942 is a skeleton
lever. Both ends of the moveable fulcrum-plate 932 are driven or pressed very
tightly in grooves 932a and 9326 cut for them in the pressure-column 923, 928,
and lever 933 while the fixed fulcrum-plate 934 has its lower end firmly pressed in
a groove 934a cut for it in the lever 933 and its upper end is firmly secured in a
recess in the fulcrum-block 930 by the clamp-plate 935. The fulcrum-plates 936
and 939, are secured in a similar manner, 939 Figure 126a, being a single plate
taking the place of 939, 939a, and clamp plates 940 shown in Figure 126. The
steel plate 943 shown in Figure 126a is firmly clamped at its right-hand end to
the lever 942 by the clamps 945 and at its left hand end to the lever 933 by the
clamps 944a, instead of the fulcrum-block 930 by clamp 944 as in Figure 126. By
making it in this way the action is much better than when it is so short as to
fasten to the said fulcrum-block 930, and it secures the lever 942 against longi-
tudinal and lateral motion equally well. The lever 933 and spring 943 must both
have clearance holes for the rods 905 and the clamp 944ª may be put either to the
right or left of the left-hand rod 905. This spring 943 acting through the lever 942
and 933 and their fulcrums receives a large part of the load on the pressure-
column 928-923 from the load on the machine.
These improvements are obviously applicable to dynamometers and weighing
machines as well as to pressure gauges.
The above improvements in dynamometers are described and parts thereof
claimed under another patent of mine of even date herewith.
Having thus described the nature of the said Invention and the mode in which
the same may be carried into effect I would have it understood that what
I claim is
First. The combination of a gauge-case 781 or 821 and a load lever 791a or 834
with a flexible fulcrum-plate 792 or 833 for connecting them.
Second. The combination of the gauge-case, main load-lever, fulcrum-block
thereof and flexible fulcrum plate connecting the same substantially as and for the
purposes set forth.
Third. The combination of the gauge-case, main load-lever, pressure column,
flexible fulcrum-plate and flexible load-transmitting-plate substantially as and for
the purposes set forth.
Fourth. In a gauge or weighing dynamometer, one or more load or transmitting
levers connected to the case and to one of the other levers by flexible fulcrum-
plates, substantially as set forth.
Fifth. In a pressure or vacuum gauge, or weighing dynamometer, the combination
of a load-pressure-column, an annular diaphragm clamped thereto, and one or more
load-transmitting-levers connected to the case and pressure-column by flexible
plates, substantially as set forth.
Sixth. The combination with a gauge-case or dynamometer-case, of a load-
pressure-column, flexible load-transmitting-plate and suitable transmitting and
indicating devices.
Seventh. In a pressure-gauge or weighing dynamometer, the combination of a
pressure-column with a lever or system of levers adapted to receive the load from
the pressure-column, and with a rotary indicator, substantially as set forth.
Eighth. The combination in a pressure-gauge, or weighing dynamometer, of a
load-pressure-column, a rotary indicator, and oue or more transmitting-levers
attached to the case by flexible fulcrum-plates, as set forth.
Ninth. The combination in a pressure-gauge, of a pressure column, a rotary
indicator, one or more transmitting-levers, and one or more flexible plates connecting
said levers, substantially as set forth.

page_text: Tenth. In a gauge or weighing dynamometer the combination of a pressure-
column, one or more transmitting-levers, an indicator, and a setting screw commu-
nicating with one of the transmitting-levers through the medium of a spring for
the purpose of adjusting the position of the indicator without opening the case,
substantially as set forth.
Eleventh. In combination with the case of a gauge or weighing dynamometer,
and suitable transmitting and indicating devices, a resisting spring and a screw-
rod, for regulating the resistance of the said spring, compensating for changes
in temperature or setting the indicator from the outside, substantially as set forth.
Twelfth. In a pressure or vacuum gauge or weighing dynamometer, a trans-
mitting-lever constructed with an upwardly projecting heel to afford an attachment
for the moving-fulcrum-plate above that of the fixed fulcrum-plate, substantially
as set forth.
Thirteenth. In a gauge or weighing dynamometer, the combination with a
suitable pressure-column, one or more transmitting-levers, and an indicator actuated
thereby of a weight mounted on one of the transınitting-levers, through the medium
of a projecting arm or standard, and having a variable effect by reason of the
elevation or depression of the lever on which it is mounted.
Fourteenth. In a gauge or weighing dynamometer, the combination with a
suitable pressure-column, one or more transmitting-levers and an indicator actuated
thereby, of a weight mounted on one of the transmitting-levers through the
medium of a projecting arm or standard, and horizontally adjustable for the
purpose of balancing the transmitting-lever or levers, and connections, substantially
as set forth.
Fifteenth. In a gauge or weighing dynamometer, the combination with a suitable
pressure-column, one or more transmitting-levers and an indicator actuated thereby,
of a weight mounted on one of the transmitting-levers through the medium of a
projecting arm or standard, and adjustable vertically, whereby the ratio of variation
in the effect of the weight by the movement of the lever on which it is mounted
may be changed as explained.
Sixteenth. In a guage or weighing dynamometer, the combination with a lever
having an elevated and projecting heel to which its moving fulcrum is attached,
of a compensating weight mounted on the said lever through the medium of a
projecting arm or standard substantially as and for the purposes set forth.
Seventeenth. A coiled band, employed as set forth to transmit motion from a
lever or rod to the rotary indicator of a gauge or weighing dynamometer substantially
as set forth.
Eighteenth. The combination in a pressure or vacuum gauge or weighing dyna-
mometer, of a pressure column, one or more transmitting levers a flexible connecting
plate or plates, a transmitting band and a rotary indicator substantially as set
forth.
Nineteenth. In a gauge or weighing dynamometer, the combination of a pressure-
column, one or more transmitting or resisting levers mounted on flexible fulcrum-
plates, a coiled transmitting band, and a spring or springs acting in opposition to
the said transmitting band as set forth.
Twentieth. In a gauge or weighing dynamometer, a hair-spring attached at one
end to the indicator or needle shaft and at the other end to a load-lever and acting
in opposition to the load to keep the parts taut and restore the indicator to zero,
substantially as described.
Twenty first. In a gauge or weighing dynamometer, the combination of the
lever 842, Hexible band 845, indicator axis 853, bearing supports 884, 884a, and
supporting and adjusting screw 882, substantially as and for the purposes set
forth.
Twenty second. The combination with the indicator-lever, of one or more
weighted arms extending either above or below said lever to offer a varying
resistance to the pressure.

page_text: Twenty third. A gauge or weighing dynamometer constructed substantially as
herein set forth.
In witness whereof I the said Albert Hamilton Emery have hereunto set my
hand and seal this eighth day of November in the year of our Lord One thousand
eight hundred and eighty three.