US3473697A

US3473697A - Liquid metering pump

Info

Publication number: US3473697A
Application number: US685128A
Authority: US
Inventors: William Dick Henderson
Original assignee: Individual
Current assignee: Individual
Priority date: 1966-11-24
Filing date: 1967-11-22
Publication date: 1969-10-21
Anticipated expiration: 1986-10-21
Also published as: GB1218347A

Description

Get. 21, 1969 w. D. HENDERSON 3,473,697

LIQUID METERING PUMP Filed Nov. 22, 1967 2 Sheets-Sheet l HQ METERING PUMP William Dick Henderson, 2328 Henderson Highway,

Winnipeg, Manitoba, Canada Filed Nov. 22, 1967, Ser. No. 685,128 Claims priority, application Canada, Nov. 24, 1966, 976,323 Int. Cl. B6711 /12 US. Cl. 222--75 3 Claims ABSTRACT OF TIE DISCLOSURE A liquid pump is described consisting of a cylinder, a piston in the cylinder and a plurality of liquid introduction lines which may be selected individually to lead liquid under pressure to one side of the piston. A compressed gas can be led to the other side of the piston for forcing the piston to eject the liquid through a discharge line. The gas space can also be vented to allow more liquid to enter and force up the piston. Shut oiT valves in the liquid introduction lines enable one or other of the liquids to be chosen for pumping at will.

This invention relates to an apparatus for pumping liquids and has particular reference to apparatus for receiving liquids from several independent supplies and delivering them without intercontamination to at using site.

In automobile service stations premium product oils are almost universally provided in sealed cans. For the lower grades of oil, several hand pumps are provided, one for each viscosity of oil, mounted over the drum containing the particular oil to which the pump relates. With the premium oil there is additional cost to the consumer because of tthe extra labour involved in sealing the oil into cans and distributing them as such. Some of the product is also lost in pouring the oil from the can into the automobile since it is virtually imposible to drain a can with any measure of efliciency in the short time available. In the second case, where oil is drawn from drums it is pumped into a measuring jug and from there dispensed into the automobile oil filler opening. The measure is open to the atmosphere and can become contaminated with dust and water. It is also difiicult to drain the measure effectively in the time interval permitted.

Improvements in the method of distributing oil have been described and claimed in my United States Patent 3,186,597 and the present invention find particular application as a pump in association with the dispensing system of that patent.

The present invention may also be employed with advantage in the liquid proportioning system disclosed and claimed in my United States Patent 3,283,957 in which it ensures that additive is alway available under a chosen pressure for metering into a second liquid.

The present invention overcomes dimculties experienced in the prior art for the feeding of multiple liquids by allowing a choice between one or other liquid to be made at any time and it has the advantage of employing compressed gas as a driving fluid and can therefore be made entirely safe in the handling of inflammable liquids.

More particularly in accordance with the present invention there is provided a liquid pump which comprises a cylinder, a piston in said cylinder, a plurality of liquid introduction lines for leading liquid under pressure into a first space defined by said cylinder on one side of said piston, means for feeding gas under pressure into a second space defined by said cylinder on the other side of said piston, valve means for alternately permitting gas feed to and venting of the second space, a liquid shut off means in each of said lines, a check valve in each of said lines nited States Patent 0 3,473,697 Patented Oct. 21, 1969 closely adjacent said first space, and means for feeding liquid from said first space under pressure of said gas in said second space.

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

FIGURE 1 shows a perspective view of one embodiment of the invention connection up to receive oil from a number of sources and to discharge it either for filling an oil dispensing unit or through a hose,

FIGURE 2 shows an enlarged view of the base portion of the pump of FIGURE 1 sectioned along line 2-2,

FIGURE 3 shows further details of the pump of FIG-

URES

1 and 2, with an arrangement to prevent sticking of the piston,

FIGURE 4 shows an automatic system for the invention,

FIGURE 5 shows an alternative embodiment of the invention with electrically operated valve means, and

FIGURE 6 shows an alternative embodiment without piston and cylinder operation.

With reference to FIGURE 1 the pump of the invention comprises a cylinder 1 preferably of tough transparent material such as an acrylic plastic to which are fastened two

end plates

2 and 3 suitably by means of bolt 4 carrying a nut 5. A piston 6 is received within the cylinder and is slidably sealed to it by an O-ring 7. The piston is also slidably sealed to the bolt 4 by means of an O-ring (not shown) within the hole 8 through which the bolt 4 passes. The space 10 formed beneath the piston can receive liquid under pressure through any one of the multiplicity of pipes 11. Only three pipes are shown, but there could be as many as required subject to space limitations. The liquid from any one of the pipes 11 enters the space 10 through a shut-off valve 35 and a check valve 36 and thence through the ports 12. Liquid can leave space 10 through either the discharge port 15 leading to hose 16 or through nozzle 17 adapted for coupling to dispenser 18 such as described in my Patent 3,186,597.

Air can be led to the space 20 above piston 6 through a pressure line 21 and a three-way valve 22. In the first position of the valve 22 the air passes through the valve and down pipe 23 through plate 3, and into the space 20. In the second position of the valve the air within space 20 can pass back out through pipe 23 and be vented at 24.

Let use now assume that a liquid is present in drum 30 (not drawn to scale) which includes a dip tube 31 and a space 32 above the liquid which can be pressurized by air introduced through a small check valve 33. Alternatively the drum 30 may be arranged at a higher level than cylinder 1 and then can supply liquid under gravity. Dip tube 31 would be replaced by a pipe leading from the bottom of drum 30 in the second instance.

Returning to FIGURE 1 let us assume that the handle 25 of three-way valve 22 is in the position to vent the space 20 and that shut-off valve 35 is open. The air pressure in space 32 then urges the liquid 34 up the dip tube 31 through the opened shut-off valve 35 through a check valve 36 and into space 10 through port 12. The liquid entering the space 10 pushes the piston 6 upwards exhausting the air in space 20. When the piston 6 reaches the top of its travel the handle 25 of valve 22 is thrown into the position to allow air under pressure to arrive through pipe 21. liquid can then be withdrawn either by opening valve 40 to allow it to flow out through hose 16 or by inserting the oil dispenser 18 into the nozzle 17. As explained in my Patent 3,186,597 the coupling of the male nozzle 41 with the female nozzle 17 allows dispenser 18 to fill under the control of the handle 42. The dispenser 18 is then removed and by raising handle 42 liquid Within the dispenser can be ejected from nozzle 41. This is all described in that patent.

If the capacity of cylinder 1 is made equal to that of the dispenser 18, then one full charge from the apparatus of FIGURE 1 will fill dispenser 18 and the piston 6 will be at the bottom of its travel when dispenser 18 is filled. Another liquid can now be led into cylinder 1 if desired by closing valve by means of handle 44 and opening one of the

other valves

35 or 35" by utrning the handles 45 or 46.

The structure of the end plate 2 can be seen in greater detail with reference to FIGURE 2. The check valves 36 should be as close as possible to the discharge port 12 with which they connect. This ensures that contamination of one liquid with another is as small as possible when the-delivery of one liquid is changed to another. The check valves 36 should be provided with fairly weak springs so that they are easily opened by the fiow of liquid from the respective supply pipe 11 even through the liquid may be supplied under quite a low pressure. The passages to the discharge hose and nozzle should be as small as possible (consistent with having adequate flow) to avoid contamination when changing from one liquid to another. The end plate 2 and the end plate 3 (not shown) are formed with grooves into which the cylinder 1 is received. This ensures that an adequate seal between the cylinder and end plate exists when the assembly is bolted up. If desired, a sealing strip may be laid down in the groove 50' to improve the seal. In order that there should be no leakage around the bolt 4 passing through the end plates, a fibre washer is placed under nut 5 and the head of the bolt. Alternatively each end plate may be formed with a groove within the hole 52 for the bolt which groove receives an O-ring 53 for sealing against the bolt shank 4 (see FIGURE 3).

An alternative embodiment of this invention is shown in FIGURE 3 in which the end plate 3 is fed not from the side but from beneath as at 60. A hose 61 controlled by valve 62 is received in the passage 60. A check valve 65 supported within space 60 by spring 66 has its head 67 very closely adjacent the top side 69 of the end plate 3. This procedure ensures an absolute minimum of contamination of one liquid by another within cylinder 1. In this drawing of FIGURE 3 the seal 68 contained within the hole 8 of the piston 6 is shown. In circumstances where the piston 6 is a tight fit on the cylinder 1 and particularly after the pump has been idle for a long period it may be desirable to include an ejector 70 for nudging the piston if it sticks at the bottom of its travel. The ejector 70 is sealed within a passage 71 by means of a small sealing O-ring 72. The ejector 70 is suitably operated by means of a lever 73 fulcrumed at 74 with a handle 75.

The apparatus may also be made to operate automatically by means of a suitable assembly such as shown in FIGURE 4. A pneumatically operating diaphragm control is connected to alter the position of the three-way valve 22. While the piston is descending, air pressure from pipe 21 is within the space 20. When the piston reaches the bottom of its travel it encounters a push rod 91 which opens a valve 92 feeding pressurized air from pipe 93 through pipe 94 to operate control 90 and switch the three-way valve into the position which vents the space 20. As the piston 6 then rises and reaches the top of its travel it will encounter a push rod which operates a valve 101 and allows air from a pipe 103 to pass through pipe 102 and reverse the position of control 90. This alters the position of the three-way valve 22 and pressurizes the space 20 above the piston 6. In order to prevent any build up of pressure in the control 90 each of its sides may be slowly bled so that by the time the piston 6 reaches the top of its travel the side which has been pressurized through pipe 94 has reached approximately atmospheric pressure. Other mechanisms will be apparent to those skilled in the art. During the descent of piston 6 the side pressurized through pipe 102 will in its turn bleed down to atmospheric pressure. It will be understood by those skilled in their art that the

valves

101 and 92 may be replaced by limited movement switches and the control of '90 be made electric. The push rods 91 and 160 are suitably sealed for sliding movement by respective O-rings 104 and 105. The advantage of having automatic operation for the pump is that a continuous supply of liquid can be drawn from it and this is particularly useful when the discharge hose 16 is being used or when the additive system of Patent 3,283,957 is employed.

In the prototype it ha been found that a pressure of 3 to 7 p.s.i.g. has been satisfactory for the liquid led into ports 12. A pressure in line 21 of 100 p.s.i.g. would deliver oil of ten to thirty SAE viscosity at a rate of 2 to 2 /2 gallons per minute.

A further way of making the device of the invention operate automatically is to adopt the procedure shown in FIGURE 5. Here the three-way valve 22 of FIGURE 1 is replaced by an electrically operated three-way valve 110. The. valve is controlled by a solenoid 111 which connects the pressure line 21 to the down pipe 23 or the vent 24 to the pipe 23. The setting of the valve is controlled by a switch 112 mounted on the nozzle 113 where the liquid is to be discharged. Switch 112 is connected through a plug 114 to the solenoid 111 fed in turn from a power supply 115. This arrangement has the advantage over the arrangement of FIGURE 4 that recharging of the cylinder 1 is under control at the discharge nozzle which may be held open until fiow of liquid ceases before the switch 112 is thrown for recharging. This ensures that the piston 6 in the cylinder 1 will come to rest at the bottom on the cylinder before the cylinder is recharged. If desired in special cases, a control valve 116 on the nozzle 113 and switch 112 may be interconnected as indicated at 118 so that when the nozzle control is released the cylinder 1 refills.

An alternative way of carrying out the invention is shown in FIGURE 6 and is especially useful for dispensing oil or antifreeze. In this, a cylinder with floating piston is no longer employed and is re laced by a pressure tank 120. There is a dip tube 121 passing into the tank which feeds a discharge hose at nozzle 128. The tank is filled through a pipe 125 via a check valve 126 from liquid contained in a storage vessel 127 arranged above the tank 120. A thin pipe 130 rises from the top of the tank 120 through a vapour condenser 131 if required.

' to a three-way valve 132. This valve vents through a pipe 135 connected with an air blast operated counter 136 to a vent 137 which for convenience can be directed into and loosely fit in opening 135 in the top of the vessel 127. Pressurized air can be led in through pipe 140.

The operation of this arrangement is as follows: the three-way valve 132 is connected to release any pressure in tank 120 connecting pipe 130 to the vent pipe 135. Liquid now flows by gravity into the pressure tank 120 and it will continue to do so until the liquid level rises in the tube 130 up to that of liquid in the vessel 127. The valve 132 is now reversed and pressurized air is fed from pipe 140 through the vapor condenser 131, if present, and into the pipe 130. Tube 130 is of small diameter but if extreme accuracy is required the pipe may be transparent and a mark made on it. The level of liquid can then be brought to this mark by reversing valve 132 when the mark is reached. A level sensitive switch may also be employed instead, for instance, to detect the presence of the liquid in tube 130 at the correct height. If the handle 141 on the nozzle is now opened, liquid will be forced through the discharge tube 123 until pressure tank 120 is empty. The arrival of air will inform the attendant that tank 120 is empty. It can now be recharged by reversing the position of valve 132. During this reversal air from the tank 120, and air in pipe 130 passes to the vent 137 through the counter 136. The counter records the fact that valve 132 has been reversed and that the tank is being recharged. Since the tank 120 is filled at each reversal and drains to the bottom of the dip tube 121, a

known measure of liquid can be discharged from the tank.

I claim:

1. A liquid pump which comprises a cylinder, a piston in said cylinder, a plurality of liquid introduction lines for leading liquid under pressure into a first space defined by said cylinder on one side of said piston, means for feeding gas under pressure into a second space defined by said cylinder on the other side of said piston, valve means for alternately permitting gas feed to and venting of the second space, a liquid shut 01f means in each of said lines closely adjacent said first space, and means for feeding liquid from said first space under pressure of said gas in said second pace, an electrically operated solenoid, means connecting said solenoid and said alternate valve means for alternating of said valve means, a switch for said solenoid, said switch thereby being capable of operatively alternating said valve means between its gas feed and gas venting position, a nozzle attached to said liquid feeding means, means mounting said switch adjacent said nozzle, means for opening said nozzle, and means connecting said nozzle opening means and said switch, said valve means being in its gas venting position when said nozzle opening means is closed and in its gas feed position when said nozzle opening means is open.

References Cited UNITED STATES PATENTS 1,327,990 1/1920 French 222-136 2,271,022 1/1942 Nelson 10352 2,348,151 5/ 1944 Rotter et a1 222-75 2,692,704 10/1954 Benz 103-52. 2,774,364 12/1956 Brobeil 222-136 ROBERT B. REEVES, Primary Examiner H. S. LANE, Assistant Examiner US. Cl. X.R.