Improvements in Prepayment Fluid Meters.
Year: 1899

page_text: Date of Application, 3rd Mar., 1899
Complete Specification Left, 2nd Dec., 1899-Accepted, 3rd Feb.,
1900
PROVISIONAL SPECIFICATION.
Improvements in Prepayment Fluid Meters.
I, HENRY GREEN, of Fishergate, Preston, in the County of Lancaster, Civil
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention has reference to prepayment fluid meters and particularly to those
of the kind described in the Specification of former Letters Patent granted to me,
No. 19067, dated August 28, 1896, an object being to provide what is known as
"price changing mechanism" whereby the quantity of fluid permitted to flow
through the meter in exchange for a given coin can be readily and definitely varied
in accordance with the current price of the fluid supplied without substituting for
one or more existing parts of the meter others of a similar kind but differing
therefrom in their relative proportions or otherwise; other objects are to provide
means for preventing a second coin being inserted in the coin shoot until the coin
previously inserted has performed its function thus preventing jamming of the
coins in the shoot and for preventing coins beyond a certain number being. inserted
and used thus permitting the operation of the prepayment mechanism before fluid
is delivered.
For this purpose, between the fluid measuring mechanism and a part driven
therefrom, the movement of which eventually causes the supply of fluid to be stopped
I interpose a pair of gear wheels having a common axis one of which is fixed to
a spindle that communicates motion to the driven part and the other of which
is loose but capable of being so coupled to the other wheel as to permit the two
wheels to move uniformly in a rotary sense relatively to each other to a limited
but variable extent and to become, during rotation, alternately disengaged from
the driving part, the re-engagement of each wheel being alternately effected by
the continued rotation of the other; by varying the extent to which either of the
two wheels can move relatively to the other before causing the re-engagement of
the other, a corresponding variation in the quantity of fluid supplied for each coin
inserted can be produced, since the greater the amount of the relative movement
permitted, the greater will be the movement of the meter mechanism while the
wheel that is fixed to the spindle and the part which stops the supply of fluid are
at rest. In some cases the price changing mechanism might be interposed between
the coin freeing or operating mechanism and that part of the apparatus the
movement of which permits the flow of fluid, but then the quantity of fluid
delivered per coin would be reduced if the relative movement of the gear wheels
were increased.
Figs. 1 to 4 of the accompanying drawings illustrate merely by way of example
an arrangement of price changing mechanism according to the present invention
applied to a dry gas meter having prepayment apparatus of the kind described in
the Specification of my said former Patent but such mechanism may be applied to
other constructions of prepayment measuring apparatus.
Fig. 1 is a plan partly in section of so much of a meter as is necessary to illustrate
my improvements, the casing being removed; Fig. 2 a section on the line x x
Fig. 1; and Figs. 3 and 4 are detail views of the gear wheels.

page_text: A worm 1 driven by the meter proper gears with a mutilated worm wheel 2 (see
Fig. 3) connected with a worm spindle 3 that gears with a worm wheel 4 fixed to
one of the hollow plugs of a compound cock such as described in the Specification of
iny said former Patent and which controls the passage of gas through the meter.
The other plug is actuated by hand through appropriate coin freed mechanism; the
two hollow plugs are so arranged one within the other that in certain relative
positions they close the gas passage, and then, if a coin be inserted through the coin
slot 5 of the meter and a handle 6 be actuated, the second mentioned hollow plug
may be actuated to a given extent, whereupon the gas passage through the compound
cock will be opened and as gas flows the first mentioned hollow plug will be actuated
by the meter proper so as, by the time the quantity of gas paid for has been
delivered, to again close the gas passage through the compound cock.
The worm 1 also gears with a second mutilated worm wheel 7 (see Fig. 4) that is
loosely mounted on a fixed stud 8, the axis of which is in line with the spindle 3;
frictional contact between the two wheels 2 and 7 is prevented by a collar or
flange 8" on the stud 8. The peripheral portion of the wheel 2 is connected to its boss
by arms or abutments 2", 2b and the wheel 7 has a pin 9 or two pins 9 and 10 screwed
through it so as to project laterally into the opening 2 in the body of the wheel 2;
the pin 9 may be a fixed pin and the pin 10 movable and screwed through any one
of a series of holes 11ª, 11, 11, etc., arranged in a part circle at equal distances
apart.
When the pins 9 and 10 (as shown in Fig. 2) abut respectively against the
arms 2 and 2 of the wheel 2, the wheels 2 and 7 will be coupled together so as to
form a perfect wheel having say 40 teeth; the teeth of each wheel overlapping the gap
in the other wheel and relative movement between them being prevented by the pins,
the two wheels will be continuously driven so long as the worm is in motion, that is
to say, as long as the gas passage of the compound cock remains open and
consumption of gas occurs. The gearing may, for example, be so proportioned that
when the wheels are thus coupled 20 feet of gas can pass through the meter between
the opening of the gas passage by means of, say, a penny and the closing of the same
by the meter. When, however, the pin 10 is shifted from the hole 11ª to the
hole 11b both wheels will travel together if the arm 2ª abuts against the pin 9 and
the wheel 2 gears with the worm 1, until the gap in the wheel 2 is over or against
the worm 1, when the wheel 2 will stop; the wheel 7, however, being in gear
with the worm 1 will then be moved relatively to the wheel 2 until the pin 10 abuts
against the arm 2b, whereupon the wheel 7 will drive the wheel 2 forward until it again
gears into the worm 1. Both wheels then again travel together until the gap in the
wheel 7 is over the worm 1 when the wheel 7 will stop, but the wheel 2 will continue
to rotate and will thus bring its arm 2* into contact with the pin 9 and then drive
forward the wheel 7 until it again gears with the worm 1. With the pin 10 in the
hole 11 such an amount of relative movement is permitted when the gap of the wheel 2
is over the worm 1 that the said wheel and the inner plug of the compound cock
cease to move whilst the wheel 7 is moved idly for a distance equal to two teeth; the
wheel 2 thus transmits the motion of the worm 1 in the ratio of 1 to 42 instead of
1 to 40, as is the case when the wheels are coupled, and thus allows 21 feet of gas to
pass through the meter between the opening and closing of the gas passage of the
compound cock instead of 20 feet. If the pin 10 be removed altogether then
the wheel 2 and the inner plug of the cock will cease working whilst the wheel 7 is
moved forward a distance equal to say 20 teeth, thus making the wheel 2 transmit the
motion of the worm 1 in the ratio of 1 to 60 and permitting 30 feet of gas to pass
for each penny.
Thus by removing or varying the position of the pin 10, the meter can be adjusted
to deliver 20 or any greater number of feet of gas up to say 30 feet in exchange for
each penny inserted. As will be understood, the limits of adjustment may vary and
the shifting of the pin 10 from one hole il to the next may be arranged to cause a
variation of the supply of more or less than one foot of gas for each penny.
In some cases, instead of the mutilated wheels 2 and 7 being driven direct from

page_text: the meter driven worm 1, they may be driven therefrom through a worm wheel, on
the spindle of which is a pinion with which both the wheels 2 and 7 gear.
The motion of the worm 1 may be conveyed to the worm spindle 3 by means of a
spring pawl 12 and ratchet wheel 12" carried respectively by the wheel 2 and the worm
spindle 3, the object being to enable the latter to be moved forward by hand
independently of the action of the meter mechanism, so as to re-set the indicator to
zero when the meter is to be used by a new customer.
Figs. 5, 6 and 7 illustrate a modified arrangement of the gear wheels, Figs. 5 and 6
being face views of the wheels 2 and 7 respectively and Fig. 7 being a plan view of
the said wheels. In this arrangement the wheel 2 which is connected with the spindle 3
is formed with a series of radial recesses 11ª, 11 etc in its peripheral portion and
the movable pin 10 which can be caused to occupy any one of the recesses is carried
by a radial arm 10" mounted on the spindle 3. The said arm is held in the position
shown in Fig. 7 with the pin 10 projecting through one of the recesses into an
a perture 7 between the arms or abutments 7 and 7b of the other wheel 7 by means of
a nut 13 screwed on the spindle end. On slackening this nut the arm 10" can be moved
back along the spindle so as to withdraw the pin 10 clear of the wheels 2 and 7;
the arm can then be swung about the spindle and moved along it so as to cause the
pin 10 to pass through any desired recess the tightening of the nut fixing it in position.
By this arrangement adjustment of the pin 10 is facilitated.
Fig. 8 is a vertical section on the line y y Fig. 1 and illustrates means for pre-
venting coins being jammed in the coin shoot and for preventing more than a limited
number being successively inserted and used to operate or release the prepayment
mechanism without the consumption of gas occurring. Fig. 9 is a view at right
angles to Fig. 8 certain parts being removed for the sake of clearness; Figs. 10
and 11 are detail views and Fig. 12 is a front elevation of the apparatus shown in Fig. 9.
To the coin shoot 14 is pivoted a balanced lever 15 the lower end of which normally
projects across the coin shoot as shown and the upper end of which may be forked
the lever being so arranged that, as the coin passes over its lower end, its upper end
will be caused to project into the upper part of coin shoot and thus prevent a second
coin being inserted until the first has been moved from and is clear of the lever. This
lever is also adapted to close the coin shoot when a given number of coins have been
inserted and the outer plug of the compound cock has been moved almost a complete
revolution relatively to the inner plug without gas thereby paid for being consumed.
In the arrangement illustrated this is effected by means of a cam 16 which is provided
with a toothed wheel 16" and is loosely mounted on a tubular extension from the
inner plug which carries an indicator disc 17, between which and the wheel 16* is loosely
mounted a sleeve 18 carrying an arm 18* having pivoted to it a link 19 that is
provided with a tooth 19 in suitable proximity to the wheel 16ª. The free end of
the link 19 carries a pin 19b that extends through a cam slot 21 in the disc 17 and
the link is pressed outwardly away from the wheel by a spring 22. The sleeve 18
also has an arm 18h which abuts against a stop 23 on the disc 17 when the tooth 19ª
is as shown out of engagement with the wheel 16*; the cam then rests against a
stop 24.
25 is a pointer carried by a spindle 26 attached to the outer plug of the
compound cock and into the path of which pointer the pin 19b extends.
In the case
of measuring apparatus adapted to receive, for example, shillings, the insertion of say
two shillings and the corresponding movement of the outer plug and attached parts by
hand without gas being consumed does not affect the position of the link 19 but, after
a third shilling has been inserted and during the subsequent movement of the outer
plug by hand the tail of the pointer 25 will cause the pin 19b to move into the con-
centric part of the cam slot 21 and thus bring the tooth 19ª into engagement with
the wheel 16 secured to the cam 16, which cam will be turned about its axis so as to
come into contact with the lever 15 and cause its hooked upper end to close the coin
shoot, thus preventing the insertion of a further coin until sufficient gas has been
consumed. As gas is consumed the disc 17 will be moved so that pin 19b again
passes into the eccentric portion of the cam slot, thereby releasing the cam 16 which
falls by its own weight and allows the lever 15 again to fall clear of the shoot.

page_text: 14 is a sharp hooked projection carried by the upper end of the pivoted coin shoot. 14
and adapted to engage with and prevent the withdrawal of a piece of tape or the like
should it be attempted to fraudulently operate the meter by means of a coin attached
to the tape or the like. The number of coins which may be inserted will vary
according to the value of the coins to be used in, or to the gearing of, the prepayment
apparatus.
It will be understood that apparatus according to this invention may be variously
modified and that some of my improvements may be used without others.
Dated this 3rd day of March 1899.
I, HENRY GREEN, of Fishergate, Preston, in the County of Lancaster, Civil
Engineer, 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 bý
the following statement :-
:-
This invention has reference to prepayment fluid meters and particularly to those
of the kind described in the Specification of former Letters Patent granted to me,
No. 19067 dated August 28, 1896, an object being to provide what is known as
"price changing mechanism" whereby the quantity of fluid permitted to flow
through the meter in exchange for a given coin can be readily and definitely varied
in accordance with the current price of the fluid supplied without substituting for
one or more existing parts of the meter others of a similar kind but differing
therefrom in their relative proportions or otherwise; other objects are to provide
means for preventing a second coin being inserted in the coin shoot until the coin
previously inserted has performed its function thus preventing jamming of the
coins in the shoot and for preventing coins beyond a certain number being inserted
and used thus permitting the operation of the prepayment mechanism before fluid
is delivered.
or
For the purpose of enabling the quantity of fluid permitted to flow through the
meter in exchange for a given coin to be varied I interpose between the fluid
measuring mechanism and a part driven therefrom, and the movement of which
eventually causes the supply of fluid to be stopped, a compound toothed wheel
composed of a pair of inutilated gear wheels having a common axis, one of which
wheels is fixed to a spindle that communicates motion to the driven part, and the
other of which is loose but capable of being so coupled to the other wheel as to
permit the two wheels to move uniformly in a rotary sense relatively to
independently of each other to a limited but variable extent and to become, during
rotation, alternately disengaged from the driving part, the re-engagement of each
wheel with the driving part being alternately effected by the continued rotation
of the other; hy varying the extent to which either of the two wheels can move
relatively to the other before causing the re-engagement with the driving part of
the other, a corresponding variation in the quantity of fluid supplied for each coin
inserted can be produced, since the greater the amount of the relative movement
permitted, the greater will be the movement of the meter mechanism while the
wheel that is fixed to the spindle and the part which stops the supply of fluid are
at rest. In some cases the price changing mechanism might be interposed between
the coin freeing or operating mechanism and that part of the apparatus the

page_text: movement of which permits the flow of fluid, but then the quantity of fluid delivered
per coin would be reduced if the relative movement of the gear wheels were
increased.
Figs. 1 to 4 of the accompanying drawings illustrate by way of example an
arrangement of price changing mechanism according to the present invention applied
to a dry gas meter having prepayment apparatus of the kind described in the
Specification of my said former Patent but such mechanism may be applied to other
constructions of prepayment measuring apparatus.
Fig. 1 is a plan partly in section of so much of a meter as is necessary to illustrate
my improvements, the casing being removed; Fig. 2 a section on the line xx
Fig. 1 and Figs. 3 and 4 detail views of the gear wheels.
A worm 1 driven by the meter proper gears with a mutilated worm wheel 2 that
is shown separately in Fig. 3 and is connected with a worm spindle 3 that gears
with a worm wheel 4 fixed to one of the hollow plugs of a compound cock such as
described in the Specification of my said former Patent and which controls the
passage of gas through the meter. The other plug is actuated by hand through
appropriate coin-freed mechanism. The two hollow plugs are so arranged one
within the other that in certain relative positions they close the gas passage, and
then, if a coin be inserted through the coin slot 5 of the meter and a handle 6 be
actuated, the secondly mentioned hollow plug may be actuated to a given extent,
whereupon the gas passage through the compound cock will be opened and as gas
flows the first mentioned hollow plug will be actuated by the meter proper so as,
by the time the quantity of gas paid for has been delivered, to again close the gas
passage through the compound cock.
The worm 1 also gears with a second mutilated worm wheel 7 that is shown
separately in Fig. 4 and is loosely mounted on a fixed tubular stud 8, the axis of
which is in line with the spindle 3; frictional contact between the two wheels 2
and 7 is prevented by a collar or flange 8ª on the stud 8. The two mutilated
wheels 2 and 7 together constitute what I have hereinbefore designated a compound
toothed wheel. The peripheral portion of the wheel 2 is shown connected to its
boss by arms 2, 2b (serving as abutments as hereinafter described) and the wheel 7
is adapted to receive two pins 9 and 10, screwed through it so as to project laterally
into the opening 2 in the body of the wheel 2; the pin 9 may be a fixed pin and
the pin 10 movable and screwed through any one of a series of holes 11ª, 11, 11,
etc., arranged in a part circle at equal distances apart. The position of the fixed pin
in relation to the arms must be such that the gaps of the mutilated wheels 2 and 7
can never overlap each other.
When the pins 9 and 10 (as shown in Fig. 2) abut respectively against the arms 2"
and 2b of the wheel 2, the wheels 2 and 7 will be coupled together so as to form a
complete wheel having say 40 teeth; the teeth of each wheel overlapping the gap
in the other wheel and relative or independent movement between them being pre-
vented by the pins, the two wheels will be continuously driven as one wheel so long
as the worm is in motion, that is to say, as long as the gas passage of the compound
cock remains open and consumption of gas occurs. The gearing may, for example,
be so proportioned that when the wheels are thus coupled 20 feet of gas can pass
through the meter between the opening of the gas passage by means of, say, a penny
and the closing of the same by the meter. When, however, the pin 10 is shifted
from the hole 11 to the hole 11b both wheels will, if the arm 2" abuts against the
pin 9 and the wheel 2 gears with the worm 1, travel together until the gap in the
wheel 2 is over or against the worm 1, when the wheel 2 will become disengaged from
the worm 1 and will stop rotating; the wheel 7, however, being in gear with the
worm 1, will then be moved relatively to or independently of the wheel 2 until the
pin 10 abuts against the arm 2b, whereupon the wheel 7 will drive the wheel 2 for-
ward until it again gears into the worm 1. Both wheels then again travel together
until the gap in the wheel 7 is over the worm 1, whereupon the wheel 7 becomes dis-
engaged from the worm 1 and will stop rotating, but the wheel 2 will continue to
otate and will thus bring its arm 2* into contact with the pin 9 and then drive

page_text: forward the wheel 7 until it again gears with the worm 1. With the pin 10 in the
hole 11 such an amount of relative movement is permitted whilst the gap of the
wheel 2 is over the worm 1 that the said wheel and the inner plug of the compound
cock cease to move during the time that the wheel 7 is being moved idly for a dis-
tance equal to two teeth; the wheel 2 thus transmits the motion of the worm 1 in
the ratio of 1 to 42 instead of 1 to 40, as is the case when the wheels are coupled
together so as to form a complete wheel, and thus allows 21 feet of gas to pass
through the meter between the opening and closing of the gas passage of the com-
pound cock, instead of 20 feet. If the pin 10 be removed altogether then the
wheel 2 and the inner plug of the cock will cease working during the time the
wheel 7 is moved forward idly a distance equal to say 20 teeth, thus making
the wheel 2 transmit the motion of the worm 1 in the ratio of 1 to 60, and per-
mitting 30 feet of gas to pass for each penny.
Thus by removing or varying the position of the pin 10, the meter can be adjusted
to deliver 20 or any greater number of feet of gas up to say 30 feet in exchange for
each penny inserted. As will be understood, the number and the positions of the
holes, and consequently the limits of adjustment, may vary and the shifting of the
pin 10 from one of the holes 11ª, 11b, etc. to the next may be arranged to
cause a variation of the supply of more or less than one foot of gas for each
penny.
In some cases, instead of the mutilated wheels 2 and 7 being driven direct from
the meter driven worm 1, they may be driven therefrom through a worm wheel,
on the spindle of which is a pinion with which both the wheels 2 and 7 gear.
The motion of the worin imparted to wheel 2 may be conveyed to the worm
spindle 3 by means of a spring pawl 12 and ratchet wheel 12ª carried respectively by
the wheel 2 and the worm spindle 3, the object being to enable the latter and the
plug geared thereto to be moved forward by hand independently of the action of the
ineter mechanism, so as to close the gas passage and to re-set to zero the indicator
which shows the value of gas paid for but unconsumed, when the meter is to be used
by a new customer. The spindle 3 may be so formed that the operation of resetting
the mechanism will be facilitated; for instance, it may be made as shown with a
squared end adapted to receive a suitable key.
In
Figs. 5, 6 and 7 illustrate a modified arrangement of the gear wheels, Fig. 5 being
an end view, Fig. 6 a side view and Fig. a detail view of the gear wheel 7.
this arrangement the wheel 2, which is connected with the spindle 3, is formed with
a series of holes 11ª, 11, etc., in its peripheral portion and the movable pin 10,
which can be caused to occupy any one of the holes, is carried by a radial arm 10
mounted on the spindle 3. Instead of holes 11ª, 11b, etc. radial recesses to serve the
same purpose may be formed at the inner circumference of the peripheral portion of
the wheel 2. The arm 10 is held in the position shown in Figs. 5 and 6 with the
pin 10 projecting through one of the holes into an aperture 7 between the arms or
abutments 7 and 7b of the other wheel 7 (Fig. 7) by means of a nut 13 screwed on
the spindle end. On slackening this nut, the arm 10" can be moved back along the
spindle so as to withdraw the pin 10 clear of the wheels 2 and 7; the arm can then
be swung about the spindle and moved along it so as to cause the pin 10 to pass
through any desired hole 11ª, 11' &c., the tightening of the nut fixing it in position.
By this arrangement adjustment of the pin 10 is facilitated. The arm 10" may be
formed with an opening 10* as shown, through which can be seen figures on the
mutilated wheel 2 indicating the amount of gas which will be delivered for each
inserted coin when the pin 10 is in any particular position.
Fig. 8 is a face view of a modification; Fig. 9 is a section on the line y y Fig. 8
and Fig. 10 is a section on the line Fig. 9. In this arrangement the mutilated
wheel 7 is provided with a fixed pin 9 and the other with an adjustable arm 10" which
The pin 9 pro-
is capable of being fixed in any desired position by suitable means.
jects laterally through the opening 2 of the wheel 2 between the arms 2 and 10%,
sufficiently to come into contact with the latter during their relative partial rotation;
by altering the position of the arm 10ª the relative or independent motion of the two

page_text: mutilated wheels can be varied. In the example, the arm 10" is mounted on the
boss of the wheel 2, the peripheral portion of which is formed with a series of
holes 11, 11, etc. the said holes being adapted to receive a screw pin 10' working in
a threaded hole formed in the thickened end portion of the arm 10%. In this
arrangement the wheels 2 and 7 are represented as gearing with a wide pinion 1-
secured upon a spindle 14", which carries a worm wheel (not shown) engaging with
the meter driven worm. The pinion 14 and spindle 14 are, in this case, provided
with a spring pawl and ratchet wheel connexion, so that the wheels 2 and 7 and the
plug that is geared to them can be operated by hand, when required.
15 is an indicator plate fixed upon the boss of the wheel 2 and marked on its face
with a series of numbers corresponding to the holes 11ª, 11b etc., the said numbers
indicating the ratio in which the wheels 2 and 7 will transmit the motion of the
meter-worin (not shown). The indicator may, however, be arranged to show the
number of feet of gas supplied for a given coin. The indicator plate is formed with
a curved slot through which the enlarged part of the arm 10ª and the screw pin 10"
extend, a pointer 15b being provided on said enlarged part to facilitate adjustment
of the arm 10".
In the case of certain meters, it might not be convenient to apply the ratchet and
pawl arrangement 12, 12ª herein before described. In such a case the worin might be
arranged on a spindle so as to be capable of moving along it in opposition to a load
such as a spring, the arrangement being such that when rotating in the direction to
drive the wheels 2 and 7, the boss of the worm will bear against a fixed abutment,
whereas the other end of the boss bears against a surface capable of yielding. Such
an arrangement is illustrated in Fig. 11 wherein 1 is the meter-driven worm engaging
with the mutilated wheels 2 and 7; it is so mounted on its spindie 1ª as to be capable
of sliding thereon its longitudinal motion in one direction being resisted by a spring 1b
arranged between it and a fixed collar 1. Longitudinal motion in the other direction
is prevented by an abutment 1" which takes the thrust when the worm is driving
the wheel 2 or 7. The worm is prevented from rotating upon its spindle by a pin le
which extends through a slot in the latter. With such an arrangement, forward
movement of the wheels 2 and 7 by hand is permitted, the worm being caused to
inove along the spindle until it is out of gear with the said wheels; on the continued
rotation of worm spindle by the meter, the said worn will work itself into gear with
the mutilated wheels, moving along its spindle until it abuts against the collar 1
when it will again drive the mutilated wheels.
The load upon the worm need only be sufficient to ensure that it will be kept in
contact with the wheels 2 and 7 so as to work itself into gear with them when
rotated by the meter; when the worm is arranged vertically the spring may in some
cases be dispensed with.
For preventing coins being jammed in the coin shoot 16 and for preventing more
than a limited number being successively inserted and used to operate or release the
prepayment mechanism without the consumption of gas occurring, I employ the
arrangement illustrated in Figs. 12 to 16 inclusive, of which Fig. 12 is a section on
the line y y Fig. 1; Fig. 13 a view at right angles to Fig. 12, certain parts being
removed for the sake of clearness; Figs. 14 and 15 are detail views and Fig. 16 is a
front elevation of the apparatus shown in Fig. 13. To the coin shoot 16 is pivoted a
counterweighted lever 16ª, the lower end of which normally projects into or across
the coin shoot as shown, and the upper end of which may be hooked, the lever being
so arranged that, as the coin in passing through the shoot bears against the lower end
of the lever, its upper end will be caused to project into the upper part of coin shoot
and thus prevent a second coin being inserted until the first has been moved from
and is clear of the lever. 16 is a cross pin which abuts against the back of the
shoot when the lever 16" is in its normal position. This lever is also adapted to
close the coin shoot, when a given number of coins have been inserted and the outer
plug of the compound cock has been moved almost a complete revolution relatively
to the inner plug without gas thereby paid for being consumed. The cock which is
provided with a stop so arranged that the plugs cannot make a complete rotation

page_text: relatively to each other. are thus prevented from becoming damaged. In the
arrangement illustrated this is effected by means of a cam 17 which is provided with
a toothed wheel 17" and is loosely mounted on a tubular extension from the outer
plug which carries an indicator disc 17h, between which and the wheel 17ª is loosely
mounted a sleeve 18 carrying an arm 18" having pivoted to it a link 19 that is
provided with a tooth 19 in suitable proximity to the wheel 17. The free end of
the link 19 carries a pin 19b that extends through a cam slot 21 in the disc 17b and
The sleeve 18
the link is pressed outwardly away from the wheel by a spring 22.
also has an arm 18b which abuts against a stop 23 on the disc 17b when the tooth 19ª
is, as shown, out of engagement' with the wheel 17"; the cam then rests against a
stop 24.
25 is an arm or the tail of a pointer carried by a spindle 26 attached to the
inner plug of the compound cock and into the path of which the pin 19b extends.
In the case of measuring apparatus adapted to receive for example shillings, the
insertion of say two shillings and the corresponding movement of the inner plug
and attached parts by hand without gas being consumed does not affect the position
of the link 19, but, after a third shilling has been inserted and during the sub-
sequent movement of the outer plug by hand, the arm or tail of the pointer 25 will
cause the pin 19b to move into the concentric part of the cam slot 21 and thus bring
the tooth 19 into engagement with the wheel 17ª secured to the cam 17, which cam
will be turned about its axis so as to come into contact with the lever 16* and cause
its hooked upper end to close the coin shoot, thus preventing the insertion of a
further coin until sufficient gas has been consumed. As gas is consumed the disc 17b
will be moved so that pin 19 again passes into the eccentric portion of the cam slot,
thereby releasing the cam 17 which falls by its own weight and allows the lever 16°
again to fall clear of the shoot. The number of coins which may be inserted will
vary according to the value of the coins to be used in, or the gearing of the prepay-
ment apparatus. 16b is a sharp hooked projection carried by the upper end of the
pivoted coin shoot 16 and adapted to engage with and prevent the withdrawal of a
piece of tape or the like should it be attempted to fraudulently operate the meter by
means of a coin attached to the tape or the like.
It will be understood that apparatus according to this invention may be variously
modified and that some of my improvements may be used without others.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed 1 declare that what I
claim is
1. Price changing mechanism for prepayment fluid meters comprising a pair of
mutilated gear wheels one of which communicates motion from the driving to the
driven part and the other of which is loose but capable of being so coupled to the
other wheel as to permit the two wheels to partially rotate relatively to or inde-
pendently of each other to a limited but variable extent and to become, during
rotation, alternately engaged and disengaged from the driving part, the re-engage-
ment therewith of each wheel being effected by the continued rotation of the other,
substantially as described.
2. Price changing mechanism for prepayment fluid meters comprising a pair of
mutilated gear wheels having a common axis and both gearing with the fluid measur
ing mechanism, of which wheels one is fixed to a spindle that communicates motion
from the fluid measuring mechanism to the part the movement of which eventually
causes the supply of fluid to be stopped and the other is capable of partial rotation
independently of said part, which two wheels can be coupled together but left
capable of relative rotary movement by one or more lateral projections or pins carried
by the one wheel and extending between abutments on the other, the arrangement
being such that the wheels will alternately pass out of gear with the driving part
that the re-engagement of each wheel therewith will be effected by the continued
rotation of the other wheel and that, by adjusting the position of one of the
projections or pins or of one of the abutments, the extent of the relative movemen

page_text: between the two wheels and consequently the quantity of fluid supplied for each coin
inserted can be altered, substantially as described.
3. The combination with a prepayment fluid meter, of price changing mechanism
constructed, arranged and operating substantially as described with reference to and
shown in Figs. 1 to 4 inclusive or modified according to Figs. 5 to 7 inclusive or
Figs. 8 to 10 inclusive respectively of the accompanying drawings.
4. In a prepayment fluid meter, the combination of a pivoted coin shoot and a
counterweighted lever pivoted thereto, the lower end of the lever normally
projecting into or across the shoot, substantially as described for the purpose
specified.
5. In a prepayment meter, the combination of a coin shoot, a counterweighted
lever whose lower end normally projects into or across the shoot, a cam that is
normally disengaged from the hand driven part, and means for causing its engage-
ment therewith when the said part has been moved relatively to the fluid-driven part
a predetermined extent, the arrangement being such that the continued relative
movement of the hand driven part then causes the cam to act upon the lever so as
to close the shoot, substantially as described for the purpose specified.
6. A prepayment fluid meter provided with means for preventing the insertion
into the coin shoot of a second coin until the previously inserted coin has performed
its function and for preventing coins beyond a certain number being inserted
without gas thereby paid for being consumed, constructed, arranged and operating
substantially as described with reference to and shown in Figs. 12 to 16 inclusive of
the accompanying drawings.
Dated this 2nd day of December 1899.
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W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.