US3622044A

US3622044A - Liquid-dispensing apparatus having pneumatically actuated indicator

Info

Publication number: US3622044A
Application number: US859235A
Authority: US
Inventors: Frederick Edward John Wilson
Original assignee: Avery Hardoll Ltd
Current assignee: Avery Hardoll Ltd
Priority date: 1968-08-20
Filing date: 1969-08-19
Publication date: 1971-11-23
Anticipated expiration: 1988-11-23
Also published as: DE1942075A1; FR2015999A1; GB1268488A; DE6932644U

Abstract

A liquid-dispensing apparatus such as a roadside fuel pump has the indicators for showing the volume of liquid dispensed and/or the price of such liquid controlled by fluid pulses produced by pulse-generating means controlled by a flow meter, the indicators being conveniently driven by fluid jet means. A fluid interlock circuit is also provided to prevent the pump from being operated if the indicators are not properly zeroised, a unit price indicator is wrongly set, or there is a fault in the control system.

Description

United States Patent Inventor Frederick Edward John Wilson Chessington, England Appl. No. 859,235

Filed Aug. 19, 1969 Patented Nov. 23,1971

Assignee Avery-Hardoll Limited Chesslngton, England Priority Aug. 20, 1968 Great Britain 39726/68 LlQUllD-DISPENSING APPARATUS HAVING PNEUMATICALLY ACTUATED INDICATOR 13 Claims, 15 Drawing Figs.

US. Cl 222/16, 222/35, 235/9l A Int. Cl B67d 5/30 Field of Search 235/9 l l,

20l; 222/32-35, l4, i6, 76, 52

V [56] References Cited UNITED STATES PATENTS 2,575,562 11/1951 Pressler 222/33 2,592,622 4/1952 Trexler 222/34 X 2,718,878 9/1955 Du Bois.... 235/200 UX 3,203,593 8/1965 James et 81. 222/76 X 3,278,082 10/1966 Thielen et al. 222/76 X 3,323,721 6/1967 Topper et al. 235/201 FS 3,371,863 3/1968 Bickford et al. 235/201 Primary ExaminerRobert B. Reeves Assistant Examiner-David A. Scherbel Attorney-Edwin E. Greigg ABSTRACT: A liquid-dispensing apparatus such as a roadside fuel pump has the indicators for showing the volume of liquid dispensed and/or the price of such liquid controlled by fluid pulses produced by pulsegenerating means controlled by a flow meter, the indicators being conveniently driven by fluid jet means. A fluid interlock circuit is also provided to prevent the pump from being operated if the indicators are not properly zeroised, a unit price indicator is wrongly set, or there is a fault in the control system.

PATENTEnunv 23 um sum 01 0F 12 PATENTEIJNUY 23 197i FIG.2.

SHEET PATENTEBuuv 23 197i sum on HF 12 PATENTEDuuv 23 Ian sum 05 or 12 PATENTEDN V 23 3. 622 O44 sum as or 12 sum 08 [1F 12 PATENTEDuuv 23 197i PATENTEDNUV 2 3 I97! sum 10 0F 12 PATENTEDHnv 23 l97l SHEET 11 [1F 1 PAIENTEI] uuv 2 3 ml SHEET 12 [1F 12 This invention relates to liquid-dispensing apparatus, for dispensing measured quantities of liquid, such as is commonly used for delivering liquid hydrocarbon fuels into the fuel tanks of vehicles driven by internal combustion engines. In such apparatus, it is usual to provide an indicating device driven by a flow meter to show, substantially continuously during a dispensing operation, the quantity of fuel dispensed, and commonly a second indicating device is provided to show, also substantially continuously, the price of the quantity of fuel dispensed.

It has been the usual practice up to the present to drive the indicating devices mechanically, which has a number of disadvantages, notably the accommodation of the driving mechanism with convenient location of the driving and driven components, and proposals have been made to employ electrical driving means. The use of electric systems, however, in-

troduces a fire danger which calls for extensive flame proofing of the electrical components, and is therefore expensive.

dicating device or devices.

The pulse-generating means may include a pulse generating device which is adjustable to vary the rate at which pulses are generated in relation to the rate of flow of liquid through the meter.

Two indicating devices may be provided, the control of one of which is effected by fluid pulses from the adjustable pulse generating device and the control of the other of which is effected by fluid pulses from a second pulse-generating device which generates pulses at a fixed rate relative to the flow of liquid through the meter.

The or each indicating device may be driven by fluid pressure in predetermined steps of movement, each step being initiated by a fluid pulse produced by the appropriate pulsegenerating device.

The or each indicating device may be driven by a fluid jet acting on a turbine wheel, the rotation of the turbine wheel being controlled by a plurality of pawls released in succession from engagement with ratchet wheel means by the fluid pulses.

According to another aspect of the invention, a liquiddispensing apparatus comprises a flow meter to measure the quantity of liquid dispensed, a pump to deliver liquid through the said meter to adispensing nozzle, and at least one indicating device driven by the meter to provide an indication corresponding to or proportional to the quantity of liquid passing through the meter, and fluid pressure means to control the starting and stopping of the pump and to control the driving of the indicating device or devices.

The invention will now be described with reference to the accompanying drawings, in which:

FIG. 1 is a front elevation of one form of liquid dispensing apparatus according to the invention;

FIG. 2 is a fluid circuit diagram showing how the indicating devices of the apparatus are driven and controlled, and also showing a fluid interlock system;

FIG. 3 is a side elevation, partly in section, of pulse generating means operated by the flow meter of the apparatus;

FIG. 4 is a sectional elevation on the line 4-4 of FIG. 3;

FIG. 5 is a sectional plan taken on the line 5-5 of FIG. 4;

FIG. 6 is an end view looking in the direction of the arrow 6 in F IG. 3;

FIG. 7 is a partial front view, on a larger scale than FIG. I, of the indicating devices;

FIG. 8 is a front view, on a larger scale than FIG. 7, of a unit price indicator shown in FIGS. 1 and 7;

FIG. 9 is a section on the line 9-9 ofFIG. 8;

FIG. 10 is a rear view of part of an endless band member 5 shown in FIGS. 8 and 9;

FIG. 11 is a front view of another part of the said band;

FIG. 12 is a rear elevation of the quantity indicating device shown in FIGS. I and 7, with its casing removed;

FIG. 13 is an end view of the parts shown in FIG. 12, with some parts in section;

FIG. 14 is a section on the line 14-14 of FIG. I3;

FIG. 15 is a detail view showing the zeroizing mechanism for the indicators;

Referring to FIG. 1 of the drawings, the liquid-dispensing apparatus comprises a casing 20 of generally rectangular shape in plan, the base portion 21 of which houses a displacement meter 22, and a pump (not shown) driven by an electric motor to supply liquid from a storage tank to the meter. An isolating valve 23 is provided between the pump and the meter 22. A horizontal arm 24 pivotally mounted at its center on the top of the casing 20 has the inlet end of a liquid delivery hose 25 fixed to one end thereof and has at its other end a support for a hose cock 26 on the other end of the hose, so that the said hose cock can be supported on the horizontal arm when not in use. A conduit 27 extending upwardly from the outlet of the meter 22 through the casing is connected by a swivel joint to a conduit 28 in the horizontal arm, the conduit 28 being connected to the inlet end of the hose 25.

A horizontally elongated slot 29 is provided in the casing 20 near the top of the latter, and in the said slot is mounted, for rotation about a vertical axis, a horizontally elongated boxlike member 31 constituting a register unit, the member 31 rotating in annular bearings 30, 30A (FIG. 7) surrounding the conduit 27. The register unit has mounted in it, on one side of its pivot, a volume indicating counter 32, and, on the other side of its pivot, a price-indicating counter 33, a unit price indicator 34 being mounted above and between the

counters

32 and 33. The

counters

32 and 33 are of the drum-type, and the unit price indicator comprises an endless band, figures on the drums and band being visible through windows on one side of the member 31, which is rotatable through so that the side having the windows can be viewed from either side of the casing 20.

The meter 22 has an output shaft rotated by the passage of liquid through the meter, the said output shaft 35 driving an air-pulse-generating assembly 36 the pulses from which control the driving of the

counters

32 and 33. The said counters are driven by air turbine devices providing a continuous driving force thereon, the air pulses generated by the assembly 36 controlling pawls cooperating with ratchet wheels in such a way that each pulse releases a pawl to permit a predetermined step of movement of a ratchet wheel.

Both the volume counter and the price counter are driven and controlled in the same manner, so the driving mechanism for only one of them will be described.

Referring to FIGS. 12 and 13, the volume counter comprises, in the conventional manner, a series of

coaxial drums

37, 38, 39, 40, the drum 37 being directly driven by the air pulses derived from the assembly 36 soas to rotate once for each unit quantity of liquid delivered and being marked to indicate fractions of a unit quantity, the drum 38 being driven from the drum 37 by conventional interrupting gear mechanism to make one-tenth of a revolution for each revolution of the drum 37, and so on.

To the drum 37 there is fixed a toothed wheel 41 serving as a turbine wheel, air under pressure being supplied through two nozzles 42 and 43, spaced circumferentially of the wheel by a distance different from the pitch of the teeth, and receiving air through a common conduit 44 so that, when compressed air is fed into the conduit 44 there is a continuous force tending to rotate the wheel 41 and the drum 37.

Also fixed to the drum 37 are five

ratchet discs

45, 46, 47, 48 and 49 each having 10 equally spaced teeth (i.e. 36 apart), the discs being mounted in relative angular positions such that corresponding teeth on adjacent discs are angularly spaced by 3.6.v

Two sets of pawls are provided, one set consisting of five aligned

pawls

51A, 51B, 51C, 51D and 51E cooperating respectively with the

ratchet discs

45, 46, 47, 48 and 49, and the other set consisting of five aligned

pawls

51F, 51G, 51H, 51] and 51K cooperating respectively with the

ratchet discs

45, 46, 47, 48 and 49. The angular interval between the set of pawls 51A to 515 and the set of pawls 51F to 51K is 18. By reason of the angular spacing of the ratchet teeth and the angular spacing of the pawl sets, it follows that by releasing the pawls of one set in succession and then releasing the pawls of the other set in succession, the drum 37 is allowed to advance in steps of 3.6".

The pawls 51A to 51B and the pawls 51F to 51K, as shown in FIG. 13, are pivoted at 52 and 53 respectively, each pawl having a tail 54, carrying a projection 55 entering an enlarged e d of a bore 56 in a mounting block 57, a conduit 58 being connected to each bore 56 and a ball 59 being provided which normally rests on a shoulder 61 in the bore but is movable by air pressure in the conduit 58 to strike the appropriate projection 55 and release the pawl. The relation of the centers of gravity of the pawls to the positions of their pivots is such that they are urged by gravity towards their ratchet-tooth-engaging positions, and stop pins 62 are provided to limit their release movement.

The conduits 58 to which air is supplied to operate the respective pawls are identified by the same letters as the corresponding pawls, air supplied to the conduit 58A releasing the pawl 51A and so on.

The manner in which air is supplied to release the pawls will now be described, with reference to FIGS. 3 to 6 of the drawings. Referring first to FIGS. 3 and 4 a part of the meter 22 is shown, together with the meter output shaft 35 and the pulse generating assembly 36. The said assembly comprises three spaced

parallel plates

63, 64 and 65 and two fixed

coaxial rings

66 and 67, the

plates

63, 64 and 65 carrying bearings for two aligned shafts 68 and 69 carrying respectively discs 71 and 72 rotatable in the

rings

66 and 67.

The meter output shaft 35 carries a spur gear 73 meshing with a spur gear 74 on the shaft 68, and the spur gear 74 drives, through a gear train 75 shown in FIG. 3, the input of a variable ratio gearbox 76 the output shaft of which is connected by another spur gear train 77 to the shaft 69. The variable ratio gearbox 76 may be of any type, particularly of one of the known types used in liquid fuel dispensing apparatus for driving a price indicating counter, and is provided with ratio setting means which will be hereinafter described.

The discs 71 and 72 are driven from the shafts 68 and 69 respectively through roller-type friction clutches 78 and 79 releasable to allow free rotation of the discs on the shafts to enable the discs to be returned to predetermined zero positrons.

The ring 66 and disc 71 constitute the pulse-generating device for operating the quantity indicating device, and the ring 67 and disc 72 constitute the pulse generating device for operating the price indicating device. The two pulse generating devices are substantially identical, and only that for operating the quantity indicating device will be described in detail.

As shown in FIG. 5, a plurality of angularly spaced radial ports 81 are provided in the ring 66, and are connected respectively to the conduits 58A to 58K in the order shown in that FIGURE. In the same radial plane as each port 81 is a second port 82 in the ring 66, all the ports 82 being connected to a gallery 83 in the ring, which gallery is connected by a conduit 84 to a source of compressed air. The disc 71, throughout its periphery, has an edge surface 85 which covers the ports 82, and has equally angularly spaced around its periphery wider edge portions 86 which also extend over the part of the ring thickness in which the ports 81 open, each portion 86 being formed with a slot 87 capable of bridging ports 81 and 82 which lie in a common radial plane. The circumferential width of the portions 86 is less than the spacing between adjacent ports 81, and the arrangement is such that as each portion 86 leaves a position in which the slot 87 therein bridges one pair of ports 81, 82 another such portion comes into a position in which the slot 87 therein bridges another pair of ports 81, 82 so that at equal angular intervals of the rotation of the disc, air pressure pulses are transmitted along the conduits 58A to 58K.

The clutch 78 comprises rollers 88 (FIG. 5) lying between an internal cylindrical surface 89 on the disc 71 and flat surfaces on a driving disc 91 fixed to the shaft 68, and urged by springs 92 into wedging engagement with the said surfaces. To release the clutch, air under pressure is caused to act on a piston 93 slidable in a cylinder 94 fixed to the plate 63 and to displace on the shaft 68 a block 95, guided by a pin on the said shaft engaging a helical slot in the block, to produce angular movement of pins 96 (FIG. 4), which displace the rollers 88 from their wedging positions.

To return the discs 71 and 72 to their zero positions after a delivery of liquid has taken place, which zero position is such that the conduit 58A will be connected through ports 81, 82 to the conduit 84 by the initial rotation of the said discs and the first pulse will be transmitted through that conduit 58A, each of the said discs carries a toothed ring 97 meshing with 11 segmental gear wheel 98 urged to rotate in one direction by a spring 99, rotation of the discs 71 and 72 by the meter rotating the segmental gear wheels in a direction to tension the springs, so that when the clutches are disengaged the discs are returned to positions determined by stops. The steps comprise pivoted arms 101 (FIG. 5) engaged by pegs 102 on the discs, the arms 101 being urged by springs 103 to positions in the paths of the pegs 102, but being displaceable against the springs 103 to allow the pegs to pass them when the discs are being rotated by the meter. It will be understood that the angular extent of the segmental gear wheels 98 is sufficient to return the discs from any positions to one in which a slot 87 in the disc will connect the conduit 58A to the conduit 84 at the next initial rotation of the disc.

The ring 67 has a ring of ports 104 corresponding to the ports 81, and a ring of ports 105 corresponding to the ports 82, the disc 72 having wide portions 106 slotted at 107 to connect pairs of these ports as described in connection with the ring 66 and disc 71, the ports 104 being connected by conduits 108 A to K, one of which is shown in FIG. 4 and marked 108, the remainder being shown only in the diagram (FIG. 2), to pawl-releasing means in the price-indicating counter similar to those in the quantity-indicating counter described with reference to FIGS. 12 and 13.

The selection of the gear ratio to be engaged in the changespeed gearbox 76 is effected in known manner by rotating a knob 109 (FIGS. 3 and 6), the knob having rotatable with it a disc 111 mounted in a circular recess 112 in a disclike housing 113 fixed to the gearbox. As will be hereinafter described, the position of this disc is used to control mechanism ensuring that delivery of liquid can take place only if the gearbox is set to provide a price computation based on a unit price shown by the unit price indicator 34, which will now be described.

The unit price indicator is shown in FIGS. 8 to 11 inclusive and includes a pair of spaced rectangular plates 114, between each of the four corners of which are mounted rollers 115 around which runs an endless flexible band 116. One of the rollers 115 is rotatable by means of an external knob 117 and has radial projections engaging in holes in the band 116 to provide a positive drive. One part of the band (FIG. 11) bears figures visible through a window in the unit price indicator to show the selected unit price, and another part thereof (FIG. 10) has formed in it a series of spaced holes 118 lying on a line inclined to the length of the band. Along one side of the space between the plates 114 there are mounted, on a line oblique to the length of the part of the band extending along that side, ten tubular socket units 115a, the said socket units being equally spaced apart by distances less than the spacing of the holes 118 in the band, and the line on which they are mounted being at a greater angle to the length of the band than the line on which the holes 1 18 lie.

Mounted between the. plates 114 parallel to the side at which the socket .units 115a are mounted is a manifold unit 119 from which project ten tubes 121, eachaligned with a different one of the socket units 115a and having their outer ends in a common plane so that they contact the inner face of the band 116. In each socket unit 115a is mounted a tubular bush 122, spring urged into contact with the outer face of the band, so as to press the band against the ends of the tubes 121. Each tube 121 leads into a common duct 123 inthe manifold unit 119 through a nonretum valve 124.

Each socket unit 115a is connected by a conduit 125 to a radial port 126 in the housing 113 fixed. to'the change-speed gearbox 76, the respective conduits being marked in the

draw ing

125 L, 125 M, 125 N, 125 O, 125 P, 125 Q, 125 R, 125 S, 125 T and 125 U, and it will be evident that, by suitably positioning the band 116, any one of the holes 118 therein can be brought into line with a particular socket unit 115a to provide a connection between that socket unit 1150 and themanifold duct 123, which connection can be made only at that position of the band. The price indications on the band are so related to the positions of the holes 118 therein that a particular connection to the manifold duct is made for each price indication.

Returning now to FIGS. 3 and 6 of the drawings, the radial -ports 126 in the housing 113 are each connected to a socket 127 opening into a shoulder 128 in the said housing which is overlapped by the edge of the disc 111 and by the edge'of a further disc 129 mounted between the disc 111 and the shoulder 128. Six of the sockets 127, to which the conduits 125 LMNOP and U are connected, are on one pitch circle,

and the remaining four sockets, to which the conduits 1'25 QRS and T are connected are on a slightly larger pitch circle as shown in FIG. 6. 1n. the disc 111 there are formed ten holes 131 with an angular spacing slightly less than that of the sockets 127, six on the same smaller pitch circle as some of the first six sockets 127 and four on the same larger pitch circle as the remaining sockets 127. The further disc for limited angular lost motion relative to the housing 113 and is urged by a spring 132 towards one end of its available relative movement, and the disc 111 is free to move through a predetermined angular distance relative to the disc 129, further movement causing it to carry the disc 129 with it, the relative angular movement in both cases being determined by I pins moving in arcuate slots. The disc 129 is formed with five holes 133 which, when the said disc is in the position to which it is urged by the spring 132, register with five of the sockets on the smaller pitch circle, and with three additional holes 134 which, when the lost motion between the two discs has been taken upregister with three of the holes in the disc 111, there being provided, at an angular position between the fifth hole 133 and the first hole 134a a radial slot which, in the first position of the disc 129 registers with the sixth socket 127 on the larger pitch circle, and, when the lost motion of the disc 111 has been taken up, remains in register with the sixth hole in the disc 111. Thus, in each of ten positions of the knob 109, corresponding to a particular gear ratio, there is a unique position in which a socket 127 is in, line with holes in both discs 111 and 129, and a tubular spigot 135 carried by one end of a flexible conduit 136, can be inserted in that socket. Only if the conduit 125 leading from the socket 127 in which .the spigot 135 has been inserted is also connected by a hole in the band 116 to the manifold duct 123 can air pass through the housing 113 and the manifold and, as will be hereinafter described, such passage of air is necessary to permit liquid to be delivered by the apparatus. The spigot 131 is retained in position, in any one of the sockets 127 in which it is inserted, by a ball detent 137.

The drums of the

counters

32 and 33 are zeroized in the known manner by levers 138, one of which is shown in FIG. 15, urged by springs 139 against heart-shaped cams 141 carried by the said drums, initial movement of the drums from their zero position, shown in FIG. 15, rocking the levers to 129 is arranged cocked positions in which they are held by latches 142. in the cocked positions of the levers 138, transfer gears 143 mounted th'erein mesh with other gears on the drums to provide transfer of motion in the usual manner.

The latches 142 for the drums of both counters are mounted on a common shah 144 (FIG. 13) which is turned to release the latches for zeroized in the following manner. A cylinder 145 has slidable in it a piston 146 urged in one direction by a spring 147 and capable of being urged in the opposite direction by air pressure in the cylinder, the rod 148 on which the piston is mounted having pivoted to it two spaced plates 149, 151 (FIGS. 13 and 14), the plate 149 being slotted longitudinally to receive a pin 152 on an arm 153 carried by the shaft 144, and the plate 151 carrying a bellcrank lever 154 one arm of which carries a pin 155 to engage a cam edge 156 on another arm carried by the shaft 144.

During a liquid delivery operation, air pressure in the cylinder holds the piston 146 in the position shown in FIG. 14, so that the spring 147 is compressed, but release of pressure from the cylinder 145, which as will be hereinafter described, occurs when a liquid delivery is initiated, allows the spring 147 to move the piston.

Initially, the pin 152 slides along the slot in the plate 149, until the pin 155 engages the cam edge 156, the slope of the cam edge being such that the bellcrank lever 154 is held against rotation by a stop 157 until the shaft 144 has been rotated far enough to release the latches 142, after which the bellcrank lever is locked by a stop pin 154a to release the shaft 144 and allow the latches to return to their operative positions. The plate 151 is formed with a cam edge 158 cooperating with a follower roller 159 on a bell crank lever 161 carried by a pivoted arm 162, and a link 163 connects the arm 162 to a pivoted plate 164 carrying the movement-limiting pins '62 for the pawls 51A' to K which control the drive of the counters and also carrying further pins 165 which, when the plates I49 and 151 are moved to zeroize the counters, are moved by rocking of the plate 164 caused by the movement of the roller 159 along the cam edge 158 to release the pawls 51A to K and so first release the cam discs 45 to 49 for zeroizing, continued forward movement of the piston rod 168 allowing the roller 159 to rise along a surface 1580 of the cam edge 158 to allow the return of the rocking plate 164 to the position shown in the drawing and allow reengagement of the pawls 51A to K with

the'cam discs

45, 49 which arenow in the required position. On the return stroke of the

plates

149 and 151 the roller 159 rides idly over the cam edge due to rocking of the bellcrank lever 161 about its pivot.

Referring now to FIG. 2 of the drawings, a description will be given of; the manner in which the liquid dispensing apparatus is controlled to provide delivery of liquid and to prevent improper operation.

An air switch valve 166 controlled by the hose cock support is arranged when the hose cock 26 is on the support to close an air pilot conduit 167 and thereby trap air under pressure in the pilot conduit 167 to hold closed a relay valve 168 isolating the apparatus from a compressed air supply connected at 169, the air pressure trapped in the pilot conduit also being applied, through a conduit 171, to the cylinder 145 to hold the zeroizing device in the cocked position. When the hose cock 26 is removed from its support, the pilot conduit 167 is connected to exhaust, allowing the air relay valve 168 to open, thereby admitting air to thecylinders 94 to allow he clutches driving the discs 71, 72 of the pulse generating assembly to engage and releasing pressure from the cylinder 145 to allow of the counters zeroizing to take place.

Air is also supplied from the relay valve 168 through a conduit 172 to the conduit 136, the conduit 172 leading to one end of a diametral passage through one end closure 173 of the cylinder 145 (FIG. 14), the other end of the said passage being connected to the conduit 136 and the diametral passage being closed by the piston rod 148 except when the piston has moved to zeroize the counters, when a circumferential groove 174 in the piston rod provides a communication between the two portions of the said diametral passage. The manifold duct 123 of the unit price indicator is connected through a conduit 170 passing through the switch valve 166, and open only when the switch valve is in the on" position, to the control inlet of a fluidic two-position switch 175 which, if pressure exists at the said control inlet is actuated to permit air from the relay valve 168 to open a second air relay valve 176 and admit air to the conduits 44 to drive the turbine wheels of the quantity and price indicators and to the conduit 84 feeding the quantity pulse generator, and the corresponding conduit feeding the price-indicating pulse generator. The opening of the relay valve 176 also supplies air to a switch operating device (not shown) for switching on the electric motor driving the pump, and to means for opening the isolating valve 23.

The

conduit

136 and 172, connecting conduits 125 L to U, and the conduit 170 thus together constitute an interlock conduit which ensures delivery of liquid only if the counters are zeroized and the unit price shown by the indicator 134 corresponds to that set by the gearbox 76.

When no pressure is available at the control inlet to the fluidic switch 175, the output from the first relay valve 168 is connected by that switch, through a connection in the switch valve which is made when the hose cock is on its support but broken when the hose cock is removed, to a fault indicator 178 of any suitable type.

When, after being removed from its support, the hose cock 26 is opened, liquid flows through the meter 22, and the meter operates the pulse-generating assembly to cause air pulses to be fed to the volume and price counters and operate them to show the quantity and value of the liquid dispensed, but such delivery of liquid can take place only if the counters have been zeroized and the unit price indicator has been set to show the correct unit price as determined by the setting of the gearbox 76. The return of the hose cock to its support after the completion of a dispensing operation interrupts the interlock conduit at the switch valve 116, allowing the fluidic switch 175 to return to its normal position and so closing the second relay valve 176, and closes off the pilot conduit enabling pressure to build up in that conduit to reset the piston 146 of the zeroizing device for the counters and close thefirst relay valve 168, the closing of the second relay valve stopping the pump, closing the isolating valve 23, and shutting off the air supply to the pulse-generating assembly.

If, while the switch valve 166 is in the off position (hose cock on support), the pilot conduit 167 or its branch leading to the zeroizing cylinder 145 should develop a fault, the first fluid relay valve 168 will be opened, and the counters will be zeroized by the spring 147, but, as the interlock conduit is closed at the switch valve 166 the second relay valve 176 will remain closed and the motor will not be switched on or the isolating valve 23 opened. Since the fluidic switch 175 is in a position to feed air through the switch valve 166 to the fault indicator 178, this indicator will be actuated to show a fault. if the pilot conduit 167 or its branch leading to the cylinder 145 develops a leak during a delivery, the delivery can be completed, but when the hose cock is returned to its support, while the second relay valve 176 will be actuated to stop the delivery, the first relay valve 168 will remain open and the fault indicator will be operated.

To prevent further use of the apparatus when the fault indicator has been operated, pressure in the conduit leading to the said indicator may be arranged to operate means overriding the normal control of the motor switch and preventing that switch from being closed.

The apparatus according to the invention may be simplified by the omission of the second fluid relay valve, the fluidic switch and the fault indicator, the remaining components being retained. With such an arrangement, the control conduit for the relay is also the interlock conduit, and runs from the relayto the zeroizing device, from the zeroizing device to the spigot 131 insertable in the housing associated with gearbox control, is connected between the said housing and the unit price indicator by multiple conduits as already described, and

runs from the unit price indicator to the switch valve where it is open when the switch is on and closed when the switch is off. A branch from the portion of the conduit between the unit price indicator and the switch valve leads to the cylinder of the zeroizing device. A conduit controlled by the relay valve is connected to the operating means for the motor switch, the operating means for the isolating valve, the fluid pulse generators and the counterdriving jets.

When the hose cock is on its support, the control conduit is closed at the switch valve and at the zeroizing device, so that the relay valve is also closed. Removal of the hose cock opens the control conduit at the switch valve, allowing zeroizing to take place, and on completion of zeroizing the remainder of the control line is opened to enable liquid to be dispensed. This simplified apparatus has less protection against faults than the apparatus first described, since leakage from the control conduit will cause the pump-driving motor to switch on although the switch valve may be in the ofi position. This disadvantage can be avoided by arranging that the conduit connected to the supply by the relay valve passes through the switch valve and is closed at that point when the hose cock is on its support.

It will be understood that the arrangements described are only examples of the manner in which the invention may be carried out, and that the fluid system may be altered in many ways without departing from the scope of the invention. For example, the selection of different paths for the fluid flow at various points in the system may be performed by fluid logic devices.

Instead of using a rotatable register unit, the said unit may be fixed and may include separate but interconnected volume and price-indicating counters on each side of the casing.

If the apparatus is required to include provision for presetting the quantity of liquid to be delivered, the valve which shuts off the delivery when the preset quantity has passed through the meter may be mounted in the boxlike member 31 and may rotate with that member, the said valve having rotatable connections to the conduit 27. The said valve may be closed by mechanism operated by the volume counter, or the price counter, or selectively by either counter, in the known manner.

To remit the rotary movement of the member 31, the various air conduits 58A to K, 108A to K and L to U may be flexible conduits.

I claim:

l. A liquid-dispensing apparatus comprising a flow meter to measure the quantity of liquid dispensed, at least one indicating device associated therewith, fluid pulse-generating means, driving means connecting said fluid pulse-generating means to said flowmeter so that operation of said meter causes said fluid pulse-generating means to produce a continuous succession of fluid pulses at a rate dependent on the quantity of liquid flowing through the meter, and step-by-step driving means for the indicating device operative to effect a step of movement of said indicating device in response to each fluid pulse generated by said fluid pulse-generating means.

2. A liquid-dispensing apparatus according to claim 1, wherein the fluid pulse-generating means further includes a fluid pulse-generating device and driving means connecting said fluid pulse-generating device to said meter, said construction providing an adjustable drive ratio to vary the rate at which fluid pulses are generated in relation to the rate of flow of liquid through the meter.

3. A liquid-dispensing apparatus according to claim 2, wherein there is provided a second indicating device, the control of at least one of said indicating devices is effected by fluid pulses from the adjustable fluid pulse-generating device and the control of the other of which is effected by fluid pulses from a second fluid pulse-generating device which generates fluid pulses at a rate which bears a constant ratio to the rate of flow of liquid through the meter.

4. A liquid-dispensing apparatus according to claim 1, wherein the driving means for the indicating device comprises an air motor including a rotor and means to produce a fluid jet to drive said rotor, ratchet means mounted to rotate with said rotor, pawl means cooperating with said ratchet means to release said pawls in sequence to pennit steps of rotation of said rotor and means operated by said fluid pulses to release said pawls.

5. A liquid'dispensing apparatus comprising a flowmeter to measure the quantity of liquid dispensed, a pump to deliver liquid through said meter to a dispensing nozzle, and at least one quantity indicating device controlled by fluid pulses from fluid pulse-generating means driven by said meter to provide an indication corresponding to or proportional to the quantity of liquid passing through the meter, and fluid pressure means to control the starting and stopping of the pump and to control the driving of the indicating device.

6. A liquid-dispensing apparatus according to claim 5, wherein there is provided an interlock system comprising a conduit connecting said source of pressure to the means for controlling the starting and stopping of the pump and to the means for controlling the indicating device, means associated with elements carried by the apparatus arranged to obstruct said conduit unless said elements are set to correct positions for liquid delivery, and a starting valve arranged to control the admission of liquid to said conduit.

7. A liquid-dispensing apparatus comprising a flowmeter to measure the quantity of liquid dispensed, a pump to deliver liquid through said meter to a dispensing nozzle, at least one indicating device, fluid pressure means operated by the meter to control the indicating device so as to provide an indication at least proportional to the quantity of liquid passing through the meter, means for controlling the starting and stopping of the pump, a source of fluid pressure and a control valve to control the supply of fluid pressure from said source both to the means for controlling the starting and stopping of the pump and to the means controlling the indicating device.

8. A liquid-dispensing apparatus according to claim 6, wherein the starting valve is operated automatically by removing a hose cock from a support, and controls the fluid pressure in a pilot conduit to actuate a fluid pressure relay through which fluid is supplied to the fluid pressure control means.

9. A liquid-dispensing apparatus according to claim 8, wherein the starting valve serves to trap fluid pressure in the pilot conduit when the hose cock is on the support, thereby closing the fluid relay valve, and acts to vent the pilot conduit to atmosphere when the hose cock is removed from the support, thereby opening the fluid relay valve.

10. A liquid-dispensing apparatus according to claim 9, wherein actuation of the fluid relay valve admits fluid pressure to switch-operating means for switching on an electric motor driving the pump.

11. A liquid pressure-dispensing apparatus according to claim 10, wherein the interlock system comprises an interlock conduit which, when unobstructed, provides a path for fluid flow to valve means controlling supply of fluid for operating the indicating device or devices and the controlling pulses for said devices.

12. A liquid pressure-dispensing apparatus according to claim 11, wherein obstructing means for the interlock conduit are associated with zeroizing means for the indicating device or devices and are arranged to provide an obstruction of the said conduit which is removed by zeroizing the said device or devices.

13. A liquid pressure-dispensing apparatus according to claim 11, wherein obstructing means for the interlock conduit are provided which are operative so long as a unit price shown on a unit price indicator is inconsistent with a gear ratio set into a change speed gearbox through which an indicating device showing the price of liquid delivered is driven by the meter.

Claims

1. A liquid-dispensing apparatus comprising a flow meter to measure the quantity of liquid dispensed, at least one indicating device associated therewith, fluid pulse-generating means, driving means connecting said fluid pulse-generating means to said flowmeter so that operation of said meter causes said fluid pulse-generating means to produce a continuous succession of fluid pulses at a rate dependent on the quantity of liquid flowing through the meter, and step-by-step driving means for the indicating device operative to effect a step of movement of said indicating device in response to each fluid pulse generated by said fluid pulse-generating means.

4. A liquid-dispensing apparatus according to claim 1, wherein the driving means for the indicating device comprises an air motor including a rotor and means to produce a fluid jet to drive said rotor, ratchet means mounted to rotate with said rotor, pawl means cooperating with said ratchet means to release said pawls in sequence to permit steps of rotation of said rotor and means operated by said fluid pulses to release said pawls.

5. A liquid-dispensing apparatus comprising a flowmeter to measure the quantity of liquid dispensed, a pump to deliver liquid through said meter to a dispensing nozzle, and at least one quantity indicating device controlled by fluid pulses from fluid pulse-generating means driven by said meter to provide an indication corresponding to or proportional to the quantity of liquiD passing through the meter, and fluid pressure means to control the starting and stopping of the pump and to control the driving of the indicating device.