Improvements in Prepayment Gas Meters.
Year: 1899

page_text: Date of Application, 16th Sept., 1899
Complete Specification Left, 16th July, 1900-Accepted, 15th Sept., 1900
PROVISIONAL DI MUITIVAT
Improvements in Prepayment Gas Meters.
I, WILLIAM COWAN, of Buccleuch Street Works, Edinburgh, in the County of
Midlothian, North Britain, Gas Meter Manufacturer, do hereby declare the
nature of this invention to be as follows:-
My invention relates mainly to improved devices for actuating the prepayment
or measuring out mechanisms of various forms of coin-freed gas meters, where a
pointer and scale price varying mechanism is used. My improvements are more
particularly applicable to those mechanisms in which the prepayment or measur-
ing out device is always moved in one direction only, such as is described, for
example, in my Patent No. 21108 of 1894. The pointer and scale device is a
modification of that described in my Patent No. 11537 of 1890. My invention
also relates to details of the prepayment mechanism.
One part of my invention consists broadly in applying a pointer and scale
price varying mechanism to a prepayment mechanism in which the coin pocket
shaft is turned continuously in one direction to set the prepayment or measuring
out device for delivery of gas, no setting back of the operating handle to the
original position being required, and in devices enabling this application to be
carried into effect.
Another part of my invention consists in providing a device enabling the
spring holding the measuring out wheel driving pawl in gear, to be tensioned only
when it is actually driving the said measuring out wheel, and therefore to be
free from tension except when the prepayment mechanism is being operated by
means of a coin.
A further part of my invention consists in a new construction of prepayment
mechanism of the type in which the coin pocket is in two parts, which are
joined by the coin itself, and in adapting to this mechanism a price varying
device of the pointer and scale type. In this mechanism the driving handle
makes a partial rotation in acting on each coin and is brought back by a reverse
rotation to the starting position.
In carrying the first part of my invention into effect according to one
modification, I provide a shaft having a handle adapted to be operated from the
outside of the meter. In this shaft is formed a coin pocket with its plane at
right angles to the axis of the shaft. The coin pocket has a through passage
adapted to let a smaller coin than that to be used pass freely through. This
coin pocket or coin wheel has formed on one side a ratchet wheel, from which
two or more teeth are omitted and at this point a deep notch is provided. An
arm is fixed to the back of the ratchet wheel, and on the end of the arm is
supported a driving pawl which projects over the measuring out wheel geared
up to the measuring out mechanism." A double armed ratchet pawl is provided
pivoted on the frame in which the coin pocket wheel is supported. This pawl
is held forward against the coin pocket wheel by a spring. A pin on the coin
pocket wheel is provided which catches on one arm of this pawl when the coin
pocket wheel is attempted to be turned by hand before the penny is placed in

page_text: the coin pocket. The other arm of the pawl lies in the deep notch on the ratchet
wheel, and this arm of the pawl is adapted to engage with the teeth of the ratchet
wheel to prevent it being turned backwards, after a penny has been placed in
the slot, and turning forward has become possible. The non return ratchet may
be provided on any other suitable part of the coin pocket shaft. When a penny
(where a penny is the proper operating coin) is placed in the coin slot, it falls
into the coin pocket, and is supported by the ends of that pocket in such a
position as to be projecting out of the pocket. This projecting part of the penny,
when the outside handle is turned, presses against the long arm of the two armed
pawl, and forces it clear of the pin on the coin pocket wheel, thus enabling
forward rotation to take place. During the forward rotation the spring presses
against the two armed pawl, the short arm of which is now engaging with the
teeth of the ratchet wheel, and this prevents the handle being turned backwards.
When about one half rotation has taken place the operating coin drops freely
out of the coin slot into a suitable receptacle. When nearly a complete rotation
of the coin pocket shaft has taken place, the short arm of the double pawl drops
into the deep notch in the ratchet wheel, and this permits the long arm of the
pawl to pass into a position to again catch the pin on the coin pocket wheel,
and prevent a second turn being given to the latter until another penny has
been placed in the slot. The measuring out or prepayment wheel is placed on
a journal whose axis is in line with the coin pocket wheel shaft, but which is
placed somewhat to the rear of that shaft. This journal is hollow and is rigidly
fixed to the supporting frame. It carries rigidly attached a semi-circular disc
whose radius is somewhat greater than that of the ratchet toothed measuring
out wheel. The pawl which is carried by the arm fixed to the coin pocket wheel
is provided with a pin against which bears the spring holding the said pawl into
gear with the measuring out wheel. This pin also rides on the edge of the
semi-circular disc, which acts as a platform holding the pawl clear of the teeth
in the ratchet measuring out wheel. A second semi-circular disc is provided,
fixed to a spindle, which passes through the hollow journal on which the measur-
ing out wheel rides, and this spindle geared up to a notched wheel provided
with a locking pawl adapted to indicate by its setting the quantity of gas which
the mechanism is set to deliver for a penny. This semi-circular disc is of
exactly the same radius as the fixed semi-circular disc, and it, also, acts as a
platform to keep the driving pawl out of gear with the measuring out wheel.
When the movable semi-circular disc is set to exactly correspond with the
position of the fixed semi-circular disc, the meter is set for supplying the
maximum quantity of gas for a penny. As the notched wheel is turned round,
so as to make the semi-circular disc overlap less and less, these latter will hold
the driving pawl up off the measuring out wheel for more than half a revolution,
so that a less quantity of gas will be supplied for each coin. The measuring
out ratchet wheel has a crown wheel formed on its face which lies opposite to
the fixed semi-circular disc. This gears with a suitable pinion wheel, driving
the screw of the meter mechanism which sets the meter free to deliver any given
quantity of gas as described in my Patent No. 21108 of 1894. The notched
wheel and spring pawl in gear with the moving semi-circular disc form a pointer
and scale, the pawl being the pointer, and the scale being arranged around the
outer circumference of the notched wheel.
In carrying the second part of my invention into effect according to one
modification, I provide the driving pawl just described adapted to operate the
measuring out wheel with a spring which is so formed as not to be in tension
when the mechanism is at the starting point, and I provide a curved segmental
plate which acts as a kind of roof. When the coin pocket wheel and the arm
carrying the driving pawl are turned the pawl operating spring, which may be
fixed to the pawl, is tensioned by passing under this roof, so that through the
whole are in which the driving pawl could be in gear with the ratchet wheel,
the pawl spring is under tension.

page_text: In carrying the third part of my invention into effect according to one
modification, I provide a suitable arranged frame and mount thereon in suitable
journals the operating shaft carrying the coin pocket. The shaft and the pocket
are preferably divided into two separate portions, and it requires the presence of
a coin before the portion connected with the handle will operate the other portion
which acts on the prepayment mechanism. The coin pocket (a coin being present
in it) has on each occasion a definite movement which may amount to one half
of a revolution on the axis, or more, as may be arranged. A segmental band is
provided to prevent the escape of the appropriate coin whilst the pocket is being
moved round to the terminal point where the band ends and so allows the coin
to drop out. But, in order to prevent the possibility of the coin being brought
back in the pocket in the event of its failure to leave it readily at the terminus,
a poised detent lever is provided at the end of the segmental band which has to
be pushed aside as the coin passes, but immediately resumes its normal position
when the coin has passed and the lever then acts as a barrier against the coin's
return. For this detent lever a spring might be substituted if desired. It is
equally necessary to prevent the coin and pocket from being turned back at
any intermediate stage of the journey, and for this purpose I form ratchet teeth
on the handle portion of the pocket. Into these ratchet teeth a pawl (which is
pivotted on the frame) gears whenever the movement of the pocket is reversed at
any point short of the terminus, but, when this has been reached, a pin on the
ratchet coming in contact with a projection on the pawl, close to the fulcrum.
instantaneously draws back the pawl and places it under the control of a poised
detent lever, or a spring, so that the pocket can now be returned to its starting
position. The attainment of that position brings about the release of the pawl
by means of a pin on the ratchet which, acting on the other side of the projection
on the pawl above mentioned, replaces the pawl in gear with the non-return
ratchet.
One end of the pocket is barred against the escape of the appropriate coin-
for example a penny-but not against the escape of a smaller coin such as a
halfpenny. And in certain cases, for the purpose of preventing the segmental
band which is employed to retain the appropriate coin in the pocket, from also
retaining the smaller coin which ought to escape, the said band may either be
placed at one end of the pocket so as to leave space for the smaller coin to drop
out, or if the band be placed round the middle of the pocket a sufficient portion
of it may be cut away to allow a smaller coin to pass out, though the appropriate
larger coin is retained, at this point, by an end projection in the pocket.
The two portions of the shaft and pocket are only united when a coin is present.
The portion which receives its motion from the handle portion, in consequence
of a coin being present in the pocket, has an arm rigidly attached to it and on
its outer end a pawl (with or without a spring) capable of gearing into the ratchet
teeth of a measuring out wheel which is mounted loose on the shaft and only
moves when driven onwards by the pawl above referred to, but does not return
when the pawl returns.
The pawl carrying arm has a spring attached which presses on the pawl and
holds it radially towards the ratchet. In a modified arrangement this spring may
be attached to the pawl itself so as to press the pawl into gear with the ratchet
by the rotation of the arm bringing the pawl and its spring under a segmental
cover plate arranged round the ratchet wheel. The measuring out wheel above.
mentioned is provided with a detent pawl to prevent its backward rotation.
This wheel has also a crown wheel formed on one side face adapted to gear with
a pinion operating the screw shaft of the prepayment mechanism.
In order to enable the quantity of gas supplied by each coin to be-varied
according to the price of gas, the extent of the measuring out wheel's advance
is limited by means of a movable semi-circular disc, before mentioned, part of
whose edge forms a platform which keeps the pawl out of gear with the ratchet
on the measuring out wheel, for a greater or less part of the pawl's movement,

page_text: as operated by the handle: This movement of the pawl arm under the action of
the handle is a movement through a fixed arc, so that a greater or less portion of
the pawl's movement is rendered idle by the platform, only that part of the
movement which takes place after the pawl has left the platform operates the
measuring out wheel and mechanism. The disc whose edge acts as a platform
as just described, is carried loose on a shaft, and in another part of its circum-
ference teeth are cut gearing with a wheel on a shaft carrying a pointer which
moves over a scale. The setting of this pointer in relation to the scale controls
the position of the platform in relation to the moving pawl. The pointer may
be fixed at any position, as desired, corresponding to the quantity of gas to be
supplied for the coin.
The coin pocket described above is provided with a circular ridge or guard,
to prevent coins being inserted in the coin pocket except at the starting position
of the coin pocket. A shutter is provided to close the coin slot when the
maximum number of coins for which the meter is intended at one time have
been inserted.
In a modified form of my pointer and scale device I provide the notched disc
before described with a locking pawl which is hinged on the supporting bracket
near the centre of the notched disc. This pawl has a tooth which passes into
the notches in the returned edge of the disc. Its outer end is bent over to form
a flat plate overlapping the edge of the disc. In this flat plate a hole is bored,
and the numbers marked on the disc corresponding to the different quantities
of gas being supplied for each particular setting of the disc appear through this
hole in the pawl plate.
итераущени
WILLIAM COWAN, of Buccleuch Street Works, Edinburgh, in the County of
Midlothian, North Britain, Gas Meter Manufacturer, do hereby declare the nature
of this invention and in what manner the same is to be performed, to be particu-
.larly described and ascertained in and by the following statement: -
My invention relates mainly to improved devices for actuating the prepayment
or measuring-out mechanisms of various forms of coin-freed gas-meters, where
a pointer and scale price-varying mechanism is used. My improvements are
more particularly applicable to those mechanisms in which the prepayment or
measuring out device is always moved in one direction only; such as is described,
for example, in my Patent No. 21108 of 1894.
The pointer and scale device is a modification of that described in my Patent
No. 11537 of 1890. My invention also relates to details of the prepayment
mechanism.
'One part of my invention consists broadly in applying a pointer and scale
price-varying mechanism to a prepayment mechanism in which the coin pocket
shaft is turned continuously in one direction to set the prepayment or measuring
out device for delivery of gas: no setting back of the operating handle to the
original position being required: and in devices enabling this application to be
carried into effect.
Another part of my invention consists in providing a device enabling the
spring, holding the measuring-out wheel driving pawl in gear, to be tensioned

page_text: only when it is actually driving the said measuring out wheel; and therefore to
be free from tension except when the prepayment mechanism is being operated
by means of a coin.
A further part of my invention consists in a new construction of prepayment
mechanism of the type in which the coin pocket is in two parts, which are-joined
by the coin itself; and in adapting to this mechanism a price-varying device
of the pointer and scale type. In this mechanism the driving handle makes a
partial revolution in acting on each coin, and is brought back by a reverse
rotation to the starting position.
In order that my invention may be clearly understood, I will now particularly
describe it with reference to the accompanying five sheets of drawings, in which,
Figures 1 to 15 illustrate the first and second parts of my invention.
Figures 16 to 24 illustrate prepayment mechanism of the type in which the
coin pocket is in two parts.
Figures 25 to 27 illustrate a modification of pointer and scale.
Referring first to Figures 1 to 15;
Figure 1 is an elevation of a prepayment mechanism and price-varying device,
looking on the back of the meter dial.
Figure 2 is a plan of the same, and
Figure 3 an elevation of the side cheek and operating handle of the same, bet
looking on the opposite side of the device.
Figure 4 is an elevation of one form of price-varying pointer and scale.
Figure 5 is a section of the coin wheel, through the liner
the arm and driving pawl, and
Figure 6 is a plan of the same.
(Fig. 6) showing
Figure 7 is an end elevation of the operating handle, coin receiver and driving
Jawl.
Figures 8 and 9 are elevations showing the coin receiver in two positions.
Figure 10 shows a separate view of the double armed ratchet pawl.
Figure 11 is an elevation of the spring tensioning and variable platform
devices, shown separated from the rest of the mechanism.
Figure 12 is a sectional plan of the same, but shewing, in addition, gearing
for operating the measuring out, and platform varying devices.
Figure 13 shows the variable platform in another position.
Figures 13 and 13 shew two views of a restraining mechanism.
Figures 14 and 15 are two views of a pointer and scale device for operating the
variable platform.
In carrying the first part of my invention into effect according to one modifica-
tion, I provide a shaft a having a handle b, adapted to be operated from the
outside of the meter. The shaft a carries a coin receiver e, which has a through
passage d, whose plane is at right angles to the axis of the shaft a (seen best in
Figures 5 and 6). This passage acts as a coin pocket for suitable coins, and
is adapted to let any smaller coin than that to be used pass freely through.
The coin receiver e has teeth e on its circumference. Two or more teeth are
omitted at g, thus forming a notch. An arm is secured to the back of the coin
receiver preferably to a boss carried by the same. Pivotally supported on the
end of this arm f is a driving pawl h, adapted to operate a measuring out wheel j
(Figures 1 and 2) in one direction. A double armed ratchet pawl k is provided
pivoted to the frame m in which the coin receiver shaft is supported (see
Figures 7 to 10 inclusive). This pawl is held forward against the coin receiver c
by a spring and a pin on e catches one arm of the pawl when
coin receiver c is attempted to be turned before the coin is placed in the coin
pocket d. The other arm q of the pawl k lies in the notch g of the coin receiver:
and the army is adapted to engage with the ratchet teeth e of the coin receiver,
to prevent it being turned backward after a coin has been placed in the slot and
turning forward has become possible. The non-return ratchet may be provided
on any other suitable part of the coin pocket shaft.

page_text: When a penny (where a penny is the proper operating coin) is placed in the
coin slot, it falls into the coin pocket d, and is supported by the ends of that
pocket in such a position as to be projecting out of the pocket, see Figures
and 9. This projecting part of the penny, when the outside handle is turned,
presses against the arm g of the pawl k and therefore forces its end p, against the
tension of the spring, clear of the pin o on the coin receiver e, thus enabling
forward rotation to take place. During the forward rotation, the spring a pulls
on the double armed pawl k, the short arm of which is now engaging with
the ratchet teeth e and this prevents the handle being turned backwards. When
about one half rotation has taken place, the operating coin drops freely out of
the coin slot into a suitable receptacle. . When nearly a complete rotation of
the coin receiver shaft a has taken place, the short arm g of the double armed
pawl drops into the notch 9 in the ratchet wheel e; and this permits the long
arm of the pawlk to pass into a position to again catch the pin o, and prevent
a second turn being given to the coin receiver until another penny has been
placed in the slot.
I have described my invention with regard to an operating mechanism provided
with a coin receiver having a coin slot with its plane at right angles to the
driving shaft and carrying an interrupted ratchet wheel: but this coin receiver
forms no part of my invention. Any suitable coin receiver that rotates with
the operating handle always in the same direction may be used.
+
The measuring out or prepayment wheel (Fig. 1, 11, and 12) is placed on a
journal, whose axis is in line with the coin receiver shaft a, but which is placed
somewhat to the rear of that shaft. This journal (Fig. 12) is hollow, and
is rigidly attached by means of a nutt to a brackets, carried from the bottom of
the frame. Rigidly attached to r is a semi-circular disc or quadrant platform w,
whose radius is somewhat greater than that of the ratchet toothed measuring-out
wheel j. The pawl h, carried by the arm f fixed to the coin receiver, is provided
with a pin, which rides on the edge of the quadrant platform, whereby the
pawl is held clear of the teeth on the measuring out ratchet wheel j. A second
quadrant platform , of the same radius as the other, is fixed to a spindle a,
which passes through the hollow journal on which the measuring out ratchet
wheel rides. This spindle carries a crown wheel which gears with a bevel
wheel 2, secured to a spindle 3, supported by a bracket from the framework.
Attached to the spindle 3 is a wheel 4, having notches on its outer circumference,
(Figures 14 and 15) provided with a locking pawl and pointer 5, and having a
scale corresponding to the notches; said notched wheel being adapted to vary
the position of the quadrant in relation to we; whereby the pawl is held out
of engagement with the wheel j, for a variable proportion of a revolution. When
the movable quadrant platform is set to exactly correspond with the fixed
platform, as shewn in Figure 13, the greatest possible number of teeth are
exposed consequently the mechanism is set for supplying the maximum quantity
of gas for a penny.
As the notched wheel 4 is turned round, so as to make the
quadrant platforms overlap one another less and less, the latter will hold the
driving pawl off the measuring-out wheet ; for a greater proportion of a
revolution (see Fig. 11) so that a less quantity of gas will be supplied for each
coin.
In some cases it has been found that if the operating handle be turned very
rapidly the measuring-out ratchet wheel moves on account of its momentum a
little beyond the point at which the driving pawl was lifted out of engagement
with the ratchet wheel. In such cases I may provide a restraining device to
overcome this difficulty. It is desirable when this is employed, to arrange the
quadrant platforms, so that the driving pawl his lifted out of engagement with
the ratchet wheel j always at the same point: the point at which the pawl
commences to engage with the ratchet wheel being variable. This arrangement
of platform differs from that herein before described with reference to Fig. 11
and 13, where the point at which the driving pawl comes into engagement with

page_text: the ratchet wheel is always the same, but the point at which the driving pawl
is lifted out of engagement with the ratchet wheel is variable.
In one form of restraining device in addition to the ordinary restraining
spring 105 (see Figure 13" and 13), I provide means whereby an extra pressure
is applied on the measuring out wheel j, shortly before the driving pawl is lifted
out of engagement with said ratchet wheel; this extra pressure being sustained
until the pawl has been lifted clear of the ratchet wheel by the fixed platform ..
To effect this extra pressure I provide a spring 106 having secured to it a wedge
shaped projection 107, adapted to engage with the pawl arm f. This projection
is pivotally attached to the boss 110 of the fixed platform, by means of a
pin 108. When the pawl arm f, in the course of a revolution, reaches the
projection 107 it presses against its inclined face 109; and so causes the projec-
tion to apply strong pressure to the face of the measuring-out ratchet wheel by
means of the spring 106.
By the time the pawl arm f has passed the end of the projection 107, the pawl
has been lifted clear of the ratchet wheel. This device forms an effective brake,
whereby motion of the measuring-out ratchet wheel is prevented; except when
driving pawl is in actual engagement with said measuring-out ratchet wheel.
A modified form of pointer and scale, adapted for such mechanisms as herein-
before described, is shewn in Figure 4. The framework of the mechanism carries
a shaft 15, to which are secured a notched wheel 16, having a scale, and a
pinion 17. Secured to the shaft which carries the movable quadrant platform
is a toothed quadrant 18, adapted to gear with said pinion 17, whereby, on turning
the notched wheel, the relative positions of the platforms may be altered. A
spring operated pointer 19, fixed to the frame, locks the notched wheel and
indicates the amount of gas being supplied for each coin inserted in the coin
pocket.
The measuring-out ratchet wheel has a crown wheel 6 formed on its face
which lies opposite to the fixed platform w. This gears with a suitable bevel
wheel 7, adapted to drive the screw 10 of the prepayment mechanism. Instead
of using the screw device as shewn in my Patent No. 21108/94, I may employ
a modification such as that illustrated in Figures 1 and 2. This device consists
in a barrel divided into two portions 8 and 9; the portion 8 is adapted to receive
longitudinal motion by means of a screw 10, when it is actuated by the measuring
out bevel wheel 7. The other portion 9 is provided with a worm wheel, geared
to the meter mechanism and registering dial; and it is adapted to receive from
the meter mechanism, as the gas passes through, a rotatory motion, which motion
it imparts to the portion S; whereby S is gradually returned to its initial
position. On the portion is formed a circular groove 11, within which rests a
forked guide 12, which is adapted to actuate a prepayment indicator or pointer,
and to open and close the gas meter valve in a manner described in my previous
patent referred to above.
In carrying the second part of my invention into effect, according to one
modification, I provide the driving pawl (seen in Figures 1, 2, 5, and 11),
adapted to operate the measuring out wheel, with a spring 13 which is so formed
as not to be in tension when the mechanism is at the starting point; and I
provide a curved segmental plate or band 14 (Figures 1, 2, 11, and 12) which acts
as a kind of roof. When the coin receiver c and the arm f, carrying the driving
pawl h, are turned, the operating spring 13, which may be fixed to the pawl h,
is tensioned by passing under this roof so that through the whole are in which
the driving pawl h could be in gear with the ratchet wheel j, the pawl spring 13
is under tension.
In order to explain how I carry the third part of my invention into effect, I
shall now particularly describe it with reference to. Figures 16 to 24 inclusive.
Figure 16 is a side elevation,
-
Figure 17 is a front elevation and
Figure 18 a plan of the mechanism.

page_text: Figure 19 is a section on X X of Figure 17, looking in the direction of the
arrow 101, and
Figure 20 a section on the same line, but looking in the opposite direction.
Figure 21 is an elevation of a modified form of coin pocket.
Figure 22 is a view looking on the bottom of the coin pocket shewn in
Figure 21.
Figure 23 is a section of the left hand portion of the pocket on the line Y Y of
Figure 21, and
Figure 24 is a view looking on the right hand portion of Figure 21. (Operating
handle not shewn.)
I provide a suitably arranged frame 21, and mount thereon in suitable journals,
the operating shaft 22, carrying the coin pocket 23. The shaft 22, which has a
slot through it corresponding to the coin slot in the coin pocket 23, and the
coin pocket 23 are in two separate portions and it requires the presence of a
suitable coin in the slot of the shaft 22 before the shaft 22 will operate the coin
pocket 23, which acts on suitable prepayment mechanism in a manner to be
hereinafter described.
One end of the coin pocket is barred against the escape of the appropriate
coin for example, a penny--but not against the escape of a smaller coin such
as a half-penny.
The two portions of the shaft and pocket are only united when a coin is
present.
The coin pocket has on each occasion that it is turned with a coin in it, a
definite movement, which may amount to one half of a revolution on the axis,
or less than this, or more as may be arranged. A segmental bracket 24
(Figures 17, 18 and 19) is provided to prevent the escape of the appropriate coin
whilst the pocket is being moved round to the terminal point, where the said
bracket 24 ends, and so allows the coin to drop out.
In certain cases for the purpose of preventing the bracket 24, which is
employed to retain the appropriate coin in the pocket, from also retaining a
smaller coin which ought to escape, the said bracket 24 may either be placed
at one end of the pocket, so as to leave space for the smaller coin to drop out,
or, if the bracket be placed round the middle of the pocket, a sufficient portion
of it may be cut away to allow a smaller coin to pass out; though the appropriate
larger coin is retained at this point by a suitable projection in the pocket. In
order to prevent the possibility of the coin being brought back in the coin pocket
in the event of its failure to leave it readily at the terminus, a poised detent
lever 25 is provided near the end of the bracket 24, which lever has to be pushed
aside as the coin passes; but which immediately resumes its normal position when
the coin has passed; said detent lever 25 then acting as a barrier against the
coin's return. A spring may be used instead of this lever 25 if desired.
It is equally necessary to prevent the coin and coin pocket from being turned
back at any intermediate stage of the journey; and for this purpose I form a
ratchet wheel 26 on the shaft portion 22, which carries also an operating
handle 30. Into ratchet wheel 26, a pawl 27, provided with a tail piece 20, and
pivotted at 28 to the frame 21, gears whenever the movement of the pocket is
reversed at any point short of the terminus. When this has been reached, a
pin 29 on the ratchet wheel 26, coming in contact with a projection 31 on the
pawl 27 close to the fulcrum 28, instantly draws back the pawl 27 from engage-
iment with the ratchet wheel 26 and places its tail-piece 20 under the control of
a spring actuated or poised lever 33, causing it to assume the position shewn by
dotted lines in Figure 19. Further rotation of the handle 30 is prevented by
the engagement of the pawi 27 with a pin 27" fixed into the frame 21.
As an
alternative arrangement the block 31" (Figure 16) attached to the lever 31 and
projecting into the slot 31 may be employed to limit the travel of the handle 30
by engaging with the top of the slot 31b. The pocket may now be returned to
its starting position and as soon as this position is reached, another pin 34,

page_text: similar to 29, comes in contact with the projection 31 and draws the pawl 27;
again into engagement with the ratchet 26, thus causing it to once more assume
the position shewn by full lines in Figure 19. Instead of using the poised
lever 33, a spring may in some cases be used.
A ring or rim of metal 35, attached to the ratchet wheel 26, and projecting a
short distance over the coin pocket, prevents an appropriate coin from passing
into the coin pocket, except when a notch 36, cut from the ring 35, leaves a
clear passage for the coin into the coin pocket: which can only occur when the
mechanism is in the proper starting position.
A shutter (not shewn) passing through a hole 40 in the coin-slot or guide 46,
may be provided to close the said slot 46, when the maximum number of coins
for which the meter is intended at one time has been inserted.
In order to return the portion 23 to its original position after having ejected
a coin, a catch 37, on the ratchet wheel 26, comes in contact with 23 as soon as
the handle 30 is moved backwards.
An arm 38, rigidly attached to the portion 23, carries on its outer end a
pawl 39 (with or without a spring), which is capable of gearing into ratchet
teeth of a measuring out wheel 41, mounted loosely on the shaft 22; said wheel
being adapted to move only when driven onwards by the pawl 39, and not to
return when the pawl 39 returns.
The arm 38 has a spring 42 attached to it, which presses on the pawl 39, and
holds it radially towards the ratchet wheel 41. If preferred a spring may be
attached to the pawl itself, and a roof plate employed, such as is described herein-
before with reference to Figures 11 and 12. The measuring out wheel 41 is
provided with a detent pawl 43, to prevent its backward rotation. A crown
wheel 44 is formed on one face of the measuring out wheel 41, adapted to gear
with a pinion operating the screw shaft of suitable prepayment mechanism.
In order to enable the quantity of gas supplied for each coin to be varied,
according to the price of gas, the extent of the measuring out wheel's advance
is limited by means of a movable semi-circular or quadrant platform 45, part of
whose edge forms a platform, which keeps the pawl 39, by means of a pin 102
carried by the pawl, out of gear with the ratchet on the measuring out wheel 41,
for a greater or less part of the movement of the pawl 39, as operated by the
handle 30. This movement of the arm 38, under the action of the handle 30 is
a movement through a fixed arc, so that a greater or less proportion of the pawl's
movement is rendered idle by the platform 45: only that part of the movement
which takes place after the pawl 39 has left the platform 45 operates the measur-
ing out wheel and mechanism. A stop 46 is provided on the guide 46 which
prevents further movement of the arm 38 when it has reached the top of its
travel.
The quadrant platform 45 is carried loosely on the shaft 22. It has formed in
one with. or attached to. it a toothed quadrant 47 (Figures 18 and 20), which
gears with a pinion wheel 48, on a shaft 49, carrying a pointer 51, which moves
over a scale 52 (Figures 16, 18, 19, and 20). The setting of this pointer 51 in
relation to the scale 52 controls the position of the platform in relation to the
moving pawl 39. The pointer 51 may be fixed at a position to correspond with
the quantity of gas to be supplied for the coin.
A modified form of coin pocket is illustrated by Figures 21 to 24. The coin
pocket is divided into two portions, a driving portion 53, having a ratchet
wheel 54 and operating handle 55, and a driven portion 56, carrying a pawl
arm 57, shewn broken off in Figure 21, which may be similar to 38 in Figures 17
and 20. The two portions are united only when a coin is present. After the
discharge of a coin the driven portion 56 may be returned by any-suitable means,
such as for instance, by securing a tail 58 to 53, adapted to engage with a
projection 59 on 56, when the operating portion 53 makes its return movement
whereby it also brings 56 back to its starting position.
A further modification of my pointer and scale device is illustrated by

page_text: Figures 25 to 27 inclusive in which Figures 25 and 26 are elevations of the scale
and indicating pawl, and Figure 27 is a detail of the latter.
I provide a notched disc 61 with a locking pawl 62, which is hinged on the
supporting bracket 63 near the centre of the notched disc 61. This pawl 62 has
a tooth 64 adapted to pass into the notches in the edge of the disc. Its outer
end 65 is bent over to form a flat plate overlapping the edge of the disc.
In this
flat plate
a hole 66 is bored, and the numbers marked on the disc, corresponding
to the different quantities of gas being supplied for each particular setting of
the disc, appear through this hole 66 in the pawl plate.
Having now particularly described and ascertained the nature of my said
invention, and the manner in which it is to be performed, I declare that what
I claim is:
1. In coin freed gas meters, means for effecting measurement of a variable
quantity of gas; consisting of an operating handle and driving pawl, both of
which perform a complete revolution in the same direction on each occasion that
the handle operates the mechanism; a ratchet wheel, suitably geared to the gas
valve of the meter, and rotated only in one direction; a pointer and scale device
adapted to adjust a variable platform in relation to a fixed platform, whereby
the pawl operates the ratchet wheel during a variable proportion of its revolu-
tion; substantially as described.
2. In coin freed gas meters, means for operating the prepayment ratchet
wheel; consisting of an operating shaft, carrying a non-return coin receiver;
means adapted to permit, one revolution of said coin receiver, when a suitable
coin is within it, and to prevent rotation either way when no coin is present;
an arm, moving with the coin receiver, provided with a pivotally attached pawl,
said pawl being adapted to engage with a prepayment ratchet wheel during a
variable proportion of each revolution; substantially as described.
3. In coin freed gas meters, a price varying device; consisting of a pointer
adapted to engage with notches cut in the periphery of a graduated disc, said
disc being suitably supported and geared to operate a quadrant platform, placed
in close proximity to a similar, but fixed, quadrant platform, their axes being
concentric, and their peripheries adapted to keep the driving pawl out of engage-
ment with the prepayment ratchet wheel for a variable proportion of each
revolution, substantially as described.
4. In coin freed gas meters, a free spring attached to the driving pawl, and
adapted to be tensioned during the operating portion of each revolution by a
curved roof plate, substantially as described.
5. In coin freed gas meters, means adapted to prevent a coin pocket from
being turned in either direction through more than a suitable angle, whether
or not a coin is present in said coin pocket, and after insertion of a coin, to
prevent said coin-pocket from being turned backward at all, until ejection of
said coin has taken place, substantially as described.
6. In coin-freed gas meters, in combination with a prepayment device; a
quadrant platform, provided with a toothed quadrant adapted to be adjusted by
a pointer and scale, whereby said quadrant platform permits the driving pawl
to operate the prepayment ratchet wheel during a variable proportion of its
revolution, substantially as described.
... th
16th don of T... 1000
MARKS & CLERK,
18, Southampton Buildings, London, W.C., Agents.