GB2224268A

GB2224268A - Fluid dispensing unit; terminating delivery after preset volume

Info

Publication number: GB2224268A
Application number: GB8825281A
Authority: GB
Inventors: Vernon K Quarve; Dennis L Mccormick
Original assignee: Graco Inc
Current assignee: Graco Inc
Priority date: 1987-07-28
Filing date: 1988-10-28
Publication date: 1990-05-02
Anticipated expiration: 2008-10-28
Also published as: GB2224268B; FR2637886B1; GB8825281D0; DE3834454A1; DE3834454C2; FR2637886A1

Description

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-5 is 1 "FLUID DISPENSING UNIT" This invention relates to units for dispensing f luid.

Various types of fluid dispensing units are well known. Pumps at petrol stations dispense fluid and measure the amount dispensed and are capable of halting upon reaching a predetermined amount to be dispensed. Similarly, manual dispensing apparatus have been used for many years for filling cars and other mechanical devices with oil and/or grease,such that an amount is mechanically dialed into a dispensing meter and that amount is dispensed. Such devices are sometimes less than desirable as they are not easily susceptible to a change in the type of units or with respect to quantities which are dispensed. Such units are also not as accurate as might otherwise be desired. Further, they tend to be complicated and in frequent need of repair due to leakage and breakage.

It is therefore an object of this invention to provide a fluid dispensing unit which is highly accurate, hand held, easy to use, reliable and inexpensive to manufacture. It is further an object of this invention to provide a fluid dispensing unit which is capable of providing information as to the total amount of fluid dispensed by the system in addition to the amount dispensed in the particular operation, 2 is and to have the unit of measurement easily field convertible.

Although the present invention is primarily directed to any novel integer or step, or combination of integers or steps herein disclosed andlor as shown in the accompanying drawings, nevertheless, according to one particular aspect of the invention to which, however, the invention is in no way restricted, there is provided a fluid dispensing unit for dispensing a fluid, the unit comprising a rotary positive displacement measuring means having an inlet and an outlet, fluid flow to the inlet being controlled by a valve; valve actuating means for opening the valve; means for latching the valve in the open position; solenoid means for releasing the 9 latch means; and means to energise the solenoid means in response to the passage of a selected fluid volume through the measuring means.

From another aspect, the invention includes a fluid dispensing unit for dispensing a predetermined volume of fluid, said unit comprising: a rotary positive displacement measuring means having an inlet and an outlet; a valve connected to said measuring means, said valve having an open position and a closed position inlet; actuating means for opening said valve; means for biasing said valve in a closed position; means for latching said valve in an open position; means for releasing said latch means in response to the passage of said predetermined fluid volume through said measuring means, W 3 is said release means comprising: a solenoid, said solenoid being unbiased; and a battery power source, said power source powering said measuring means and energizing said solenoid, said solenoid releasing said latch means upon dispensing of said predetermined volume of fluid.

In an embodiment of the invention, fluid to be dispensed flows through a fluid motor having a rotatable multi-lobed rotor and lobed housing which cooperate to form a positive displacement motor capable of highly efficiently and accurately measuring the amount of fluid flowing therethrough. A magnet is located on the shaft of the fluid motor. Rotation of the magnet is sensed by a reed switch located in the housing of the fluid motor. The reed switch counts the number of rotations of the fluid motor which is directly proportional to the amount dispensed through the fluid motor. Appropriate electronics convert the number of rotations into the amount of fluid dispensed and that amount is compared with a selected amount which has been entered via a keypad on the dispensing unit.

When the selected amount is reached, a 20 to 50 millisecond pulse of electricity is sent to a solenoid which, during its brief energisation, releases a valve to close. The valve had been previously manually actuated by the operator against a reasonably strong spring and latched in the open position. Thus, the force necessary to positively 4 close the valve is in effect supplied by the operator during the opening motion and is stored in the spring. The solenoid thus merely serves to release the spring and allow the valve to close of its own volition.

How the invention may be carried into effect is hereinafter particularly described with reference to the accompanying drawings, in which:- Figure 1 is a cross-section of a fluid dispensing unit according to the present invention; Figure 2 is a cross-section of a second embodiment of unit according to the present invention; Figure 3 is a schematic representation of the electronic package for units according to the present invention; and Figure 4 is a cross-section of a fluid motor forming part of the units of Figures 1 and 2.

The first embodiment of fluid dispensing unit 10 (Figure 1) according to the present invention has a fluid motor housing 12 with a positive displacement fluid motor 14 located therein. Fluid is supplied to the motor 14 through an entry port 28 and leaves through an exit port 30. Fluid motor 14 (Figure 4) has a central four-lobed rotor 16 keyed to a shaft 20 and a surrounding housing 18 with five recesses therein. This type of fluid motor is in general well known in the art and will not be described more fully hereinafter. This type of motor is, however, particularly suited for accurate v measurement because the rotation of the shaft and rotor corresponds to the quantity of fluid passing through the Because of the construction of this motor, no rotating seals are necessary and hence the unit is practically immune from leaks. Other types of positive displacement motors such as gear types are also capable of functioning as desired.

Located on the end of the shaft 20 is a permanent magnet 22 which rotates with the shaft and triggers a reed switch 26, located in the fluid motor housing 12. In addition, a stationary coil 24 surrounds the magnet 26, so that a small alternating current can be obtained.

Below the fluid motor 14 and ports 28 and 30 is an actuator 40 movable to open and close a fluid valve (not shown) by which the supply of fluid to the entry port 28 is controlled. The actuator 40 is connected to or integral with an actuator sleeve 38 which 4t one end projects slightly from the housing. The sleeve 38 is slidable upon a tubular member secured by a bracket to the fluid motor housing 12. This bracket also carries a solenoid 32 whose armature projects through the tubular member and has an enlarged cylindrical part 34 with a part-conical ramp 32a leading to a narrower portion. A light compression spring 36 urges the armature out of the solenoid 32. The tubular member has a series of holes in which detent balls 37 are held captive. When the detent balls 37 are aligned with the -3 6 J0 is enlarged part 34, they locate in an internal annular groove 38a in the sleeve 38. A strong compression spring 31 acts between the projecting end of the sleeve 38 and the stationary tubular member.

Initially, the detent balls 37 in the holes in the stationary tubular member engage the narrower portion of the armature and do not enter the groove 38a, thus allowing the actuator sleeve 38 to project fully and hold the actuator 40 in the valve closed position (not shown). Manual pressure upon the projecting end of the sleeve 38 compresses the spring 31 until the detent balls are aligned with the groove 38a. At this point, the spring 36 presses the armature part 34 so that the ramp 32a moves to the left (Figure 1) pressing the detent balls 37 into the groove 38a. Thereafter, the balls are held in the groove 38a by the enlarged armature part 34. The actuator 40, having been moved to the right (Figure 1) opens the valve for the supply of fluid to the entry port 28 of the fluid motor 14.

As fluid passes through the device, the rotor 16 is rotated with the shaft 20 and magnet 22. The latter's rotation is detected by the reed switch 26 and counted in an electronic package 42 to give an indication of the amount of fluid dispensed. When a predetermined amount of fluid has been dispensed, the solenoid 32 is energised, pulling the armature to the right against the spring 36.

Y 1 1 7 The enlarged armature part 34 acts as a release trigger, allowing the detent balls 37 to move inwardly along the ramp 32a and out of the groove 38a. This releases the sleeve 38 for movement to the left under the pressure of the spring 31. Movement of the actuator sleeve 38 to the left pulls the valve actuator 40 to close the valve.

The valve controlling fluid flow can be any suitable valve. An unbiased valve is preferred, but one that is biased to the closed position can be used, for example, one such as is shown in Figure 2.

The electronic package 42 (Figure 3) is located in the top of housing 12, and_ is comprised generally of a central processing unit (CPU), driven bya battery, a liquid crystal or similar display 46, a connection to the reed switch 26, a connection to the solenoid 32, and a keypad 48. The electronics used in this device are generally conventional and need not be described more fully ereinafter. In operation, a user entersthrough keypad 48 an amount of fluid which he wishes to dispense. The fluid valve is then opened by pressure on the actuator sleeve 38, as described above. Fluid turns the fluid motor 14, rotating the magnet 22. When the reed switch has sent an appropriate number of pulges to the CPU 44, a 20 to 50 millisecond burst of electricity is sent to energise solenoid 22, thereby releasing the trigger so that the spring 31 moves the actuator to close the valve. The display 46 can be set to display the 1 5 4 8 amount to be dispensed, the amount that has been dispensed so far, or even a cumulative amount which the device has dispensed over time, for example since the container from which it dispenses was filled. CPU 44 may be easily programmed to change the units of measurement as desired, e. g. from gallons to litres.

The battery may be a primary battery or a rechargeable battery. In the latter case, the alternator formed of the coil 24 and magnet 22 and driven by the fluid motor 14 can be used to provide alternating current to be rectified to recharge the batteries,thereby extending the life of the device for almost an indefinite period. The display 46 is preferably digital and may show both the amount of fluid dispensed and the preset amount which has been punched in via the keypad 48.

In a second and preferred embodiment shown in Figure 2, a fluid dispensing unit 110 is generally similar to the unit 10, with fluid motor housing 112, which contains therein a fluid motor 114, similar to the motor 14 (Figures 1 and 4). Shaft 120 of fluid motor 114 has a magnet 122 at one end, the rotation of which is sensed by reed switch 126. A coil 124 is placed around rotating magnet 122 if a small alternator is needed, the output of which can be rectified and used to recharge the circuit batteries. An inlet port 128 directs incoming fluid to the fluid motor 9 114 and an outlet port 130 directs the fluid to wherever appropriate.

A valve assembly 150 is provided having a fluid valve 152 therein which is biased to the closed position by a strong compression spring 131. Valve 152 is actuated by a hand trigger 154, which pivots on a hinge 156. Pivoting trigger 154 counterclockwise about hinge 156 (Figure 2) simultaneously opens fluid valve 152 starting flow and compresses spring 131. A slotted, pivoted latch 158 connects the trigger 154 to a pivot pin 157 on the valve housing. The trigger 154 has a pin 162 engaged in a slot in the latch 158, which slot has a side extension 160 so that with the trigger closed, the operator can pivot the latch 158 placing the side extension 160 around pin 162, thus holding the trigger 154 closed and the fluid valve 152 open. Fluid will continue to be dispensed until the preset volume has been reached. The electronics package 142 will then send an electrical pulse to a solenoid 132, whose armature is drawn into an actuator band 140 to pivot the trigger latch 158 so that the side extension 160 releases the pin 162 and the trigger 154 is pushed away from the valve housing and the valve 152 is closed by the spring 131.

To provide the pulse to the solenoid 132 at appropriate time, the fluid dispensing unit 110 -5 th electronic package 142 similar to the package 42.

It is contemplated that various changes and modifications may be made to the fluid dispensing unit without departing from the scope of the invention as defined by the following claims.

Whilst it is preferred that the battery supplying power to the electronic package be rechargeable, so as to use the electric power generated in the coil 24 or 124 by rotation of the magnet 22 or 122, the battery could be a primary battery or a solar cell.

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Claims

C L A I M S

1. A fluid dispensing unit for dispensing fluid, the unit comprising a rotary positive displacement measuring means having an inlet and an outlet, fluid flow to the inlet being controlled by a valve, valve actuating means for opening the valve, means for latching the valve in the open position, solenoid means for releasing the latch means, and means to energise the solenoid means in response to the passage of a selected fluid volume through the measuring means.

2. A unit as claimed in claim 1, wherein the actuating means comprises a manually actuatable handle.

3. A unit as claimed in claim 1 or 2, wherein the measuring means comprises a fluid motor rotatable by fluid flow from the inlet to the outlet.

4. A unit as claimed in claim 3, wherein the fluid motor has a shaft whose rotations are counted to provide a measure of fluid volume passing through.

5. A unit as claimed in claim 4, wherein the shaft carries a magnet whose rotations are counted by a stationary reed switch near the magnet.

6. A unit as claimed in claim 3, 4 or 5, wherein the fluid motor is a lobed fluid motor.

7. A unit as claimed in any preceding claim, comprising means for displaying the volume of fluid dispensed.

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8. A unit as claimed in any preceding claim comprising keyboard means for entering a selected volume into the measuring means.

9. A unit as claimed in any preceding claim comprising means for manually releasing the valve latching means.

10. A unit as claimed in any preceding claim, including means for biasing the valve to the closed position.

11. A unit as claimed in any preceding claim, in which the means to energise the solenoid means is battery powered.

12. A fluid dispensing unit substantially as hereinbefore particularly described and illustrated in Figures 1, 3 and 4 of the accompanying drawings.

13. A fluid dispensing unit substantially as hereinbefore particularly described and illustrated in Figures 2, 3 and 4 of the accompanying drawings.

14. A fluid dispensing unit for dispensing a predetermined volume of fluid, said unit comprising: a rotary positive displacement measuring means having an inlet and an outlet; a valve connected to said measuring means, said valve having an open position and a closed position inlet; actuating means for opening said valve; means for biasing said valve in a closed position; means for latching said valve in an open position; means for releasing said latch means in response to the passage of said predetermined fluid volume 1 13 through said measuring means said release means,comprising: a solenoid, said solenoid being unbiased; and a battery power source, said power source powering said measuring means and energizing said solenoid, said solenoid releasing said latch means upon dispensing of said predetermined volume of fluid.

15. Any novel integer or step, or combination of integers or steps, hereinbefore described or shown, irrespective of whether the present claim is within the scope of, or re-lates to the same or a different invention from that of the preceding claims.

k 1 Published 1990 atThe Patent Office. State House. 66171 High Holborn, London WCIR 4TP. Further copies maybe obtained from The Patent Office. Sales Branch, St Mary Cray, Orpington, Kent BR5 3RD. Printed by Multiplex techniques lid, St Mary Cray. Kent. Con. 1187