Air-Operated Pump
An air-operated pump for pumping material such as oil or grease. The pump is powered by an air motor which operates to reciprocate a piston and plunger to effect a pumping action. The air motor is modular in that the air valve system is contained in a single housing fastened to the pump head. The housing is removable as a unit from the pump head to facilitate servicing of the air valve system.
Latest LINCOLN INDUSTRIAL CORPORATION Patents:
This invention relates generally to lubrication equipment, and more particularly to pumps operated by air motors for pumping lubricant such as oil or grease.
Accordingly, there is a need for an improved pump design which facilitates servicing of an air valve system of a pump of the type described above.
SUMMARY OF THE INVENTIONIn one embodiment, this invention is directed to an air-operated pump for pumping material, particularly a lubricant such as oil or grease. The pump comprises a head defining a cylinder, a piston reciprocal up and down in the cylinder, and a pump plunger having an upper end connected to the piston and a lower end. An elongate pump tube is connected to the head and surrounds the plunger. The pump tube extends down below the lower end of the plunger. An air motor module supplies air under pressure to the head for reciprocating the piston in the cylinder to move the pump plunger up and down in the pump tube through pumping strokes. The air motor module comprises a housing at one side of the head and an air valve system in the housing for supplying air under pressure to the head for reciprocating the piston in the cylinder. The air valve system comprises air signal valves, a relay valve and a power valve. A fastening system is provided for securing the housing to the head such that the housing may be removed as a unit from the head (e.g., to facilitate servicing of the air valve system).
In another embodiment, an air-operated pump of this invention comprises a head comprising a cylinder, a piston reciprocal up and down in the cylinder, and a pump plunger extending down from the piston, the plunger having an upper end connected to the piston and a lower end. An air motor module is provided for supplying air under pressure to the head for reciprocating the piston in the cylinder to move the pump plunger up and down through pumping strokes. The air motor module comprises a housing at one side of the head. The housing comprises solid one-piece monolithic rectangular block. The air motor module also includes an air valve system in the housing for supplying air under pressure to the head for reciprocating the piston in the cylinder. The air valve system comprises air signal valves, a relay valve and a power valve received in respective bores in the block. One or more fasteners are provided for securing the block to the head such that the block and covers may be removed as a unit from the head.
Other objects and features will be in part apparent and in part pointed out hereinafter.
Corresponding reference numbers indicated corresponding parts throughout the drawings.
DETAILED DESCRIPTIONIn general, and referring to
In the embodiment shown in
Referring to
In the illustrated embodiment, the pump tube 125 comprises an upper tubular part 201 attached to the lower end cap 173 of the pump head 105 and a cylindrical bearing 205 fitted in the upper tubular part 201 for supporting the plunger as it reciprocates. The bearing 205 extends up from the pump tube into an opening in the lower end cap 173. The pump tube 125 also has a lower part comprising a sleeve 211 having a threaded sealing fit at its upper end with the upper tubular part 201 of the pump tube. The upper and lower parts of the pump tube 201, 211 are co-axial with the plunger 121 and spaced from the outer surface of the plunger to define upper and lower pumping chambers 215, 217 above and below the location 195 where the first check valve 183 seals against the inside surface of the pump tube sleeve 211. The upper pumping chamber 215 communicates with the check valve chamber 181 via one or more holes 221 in the plunger 121 for flow of lubricant from the check valve chamber into the upper pumping chamber. Lubricant is expelled from the upper pumping chamber 215 via an outlet 225 (
A second check valve 231 is provided at the lower end of the pump tube 125 at a location spaced below the lower end of the plunger 121 for controlling flow into a lower pumping chamber 217. The second (lower) check valve 231 comprises a valve body 235 having a sealing fit in the lower end of the pump tube sleeve 211, an axial flow passage 239 through the valve body, a valve seat 241 at the upper end of the flow passage, and a ball valve 243 movable between a closed position in which it is seated to block flow through the flow passage 239 to an open position spaced from the seat to allow flow into the lower pumping chamber 217. A seal 245 around the valve body seals against the inside wall of the sleeve 211 of the pump tube.
As illustrated in
The fastening system 151 for securing the air motor module 131 to the pump head 105 comprises, in one embodiment, one or more fasteners 285 (e.g., four threaded fasteners are shown in
The housing 141 has an air inlet 301 (
The air signal valves 315, 317 are pressure-differential valves and function to signal or detect the position of the piston 111 as it reciprocates in the cylinder 107. The first (upper) signal valve 315 is adapted to detect the position of the piston as it approaches the upper end of the cylinder, and the second (lower) signal valve 317 is adapted to detect the position of the piston as it approaches the lower end of the cylinder. An exemplary first (upper) signal valve 315 is shown in
Referring to
Referring to
The various exhaust ports of the air valve system 145 communicate with the annular space 161 and exhaust outlet 165 (
In use, the pump 101 is mounted in an operating position, e.g., on a container containing a supply of lubricant such as oil. A cycle of operation of the pump is described below.
At the start of an upstroke of the piston 111 in the cylinder 107, the air valves of the air module are positioned as shown in
As the piston 111 moves up in the cylinder 107 (
As the piston 111 moves toward the top of its upstroke, it moves past the small upper cylinder port 359 in the upper chamber 115 of the cylinder. When this happens, air pressure in the lower (pressurized) chamber 117 moves the ball seal 345 of the upper air signal valve 315 away from its seat to open the relay port 373 and close the exhaust port 365. In response, the spool 441 of the relay valve 321 moves to open the air inlet port 405 and the power valve port 421 to pressurize passage 431 to the upper end of the power valve 325. The resulting increase in pressure causes the spool 501 of the power valve 325 to shift to the position shown in
As the piston is driven down, the two small upper cylinder ports 357, 359 are pressurized, in response to which the pressure differential across the upper signal valve 315 causes the valve member 337 to move down to a position in which the diaphragm and ball seals 341, 345 are seated to close the passages 351 and 353 and to open the relay valve port 373 and exhaust port 365. At the same time, the lower chamber 117 of the cylinder below the piston is open to atmosphere via the lower large cylinder port 533. The lower signal valve 317 is in communication with the lower chamber 117 of the cylinder via the lower small cylinder ports 385, 387. Because the pressure in the lower chamber is open to atmosphere no significant positive pressure is applied to the lower signal valve.
As the piston 111 moves down (
As the piston moves toward the bottom of its downstroke, it moves past the lower small cylinder port 385 in the cylinder. When this happens, air pressure in the upper (pressurized) chamber 115 moves the ball seal 345 of the lower air signal valve 317 away from its seat to open the relay port 397 and close the exhaust port 391. In response to the pressure in the upper cylinder chamber 115, the spool 441 of the relay valve 321 moves to open the port 405 admitting main air line pressure to the power valve port 425 to pressurize passage 433 to the lower end of the power valve 325. The resulting increase in pressure causes the power valve 325 to shift up to the position shown in
It will be apparent from the above description that an air-operated pump of this invention is an improvement over prior systems of the type shown in
When introducing elements of the present invention or the preferred embodiment(s) thereof, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of the elements. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Further, the terms “upper”, “lower”, “down” and “up” are used for convenience only, and it will be understood that other orientations (e.g., non-vertical or reverse) are possible.
In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.
As various changes could be made in the above constructions, products and methods without departing from the scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.
Claims
1. An air-operated pump for pumping material, particularly a lubricant such as oil or grease, said pump comprising:
- a head comprising a cylinder;
- a piston reciprocal up and down in the cylinder;
- a pump plunger having an upper end connected to the piston and a lower end;
- an elongate pump tube connected to the head and surrounding the plunger, said pump tube extending down below the lower end of the plunger; and
- an air motor module for supplying air under pressure to the head for reciprocating the piston in the cylinder to move said pump plunger up and down in the pump tube through pumping strokes;
- said air motor module comprising a housing at one side of the head, an air valve system in the housing for supplying air under pressure to the head for reciprocating the piston in the cylinder, said air valve system comprising air signal valves, a relay valve and a power valve, and a fastening system for securing the housing to the head such that the housing may be removed as a unit from the head.
2. An air-operated pump as set forth in claim 1 wherein said housing comprises a block recessed to receive said air signal valves, relay valve and power valve.
3. An air-operated pump as set forth in claim 2 wherein said air signal valves are mounted in recesses in the block adjacent upper and lower ends of the block, said housing further comprising removable upper and lower covers covering said recesses, the covers being removable to provide access to said signal valves.
4. An air-operated pump as set forth in claim 2 wherein said relay valve is mounted alongside said power valve in respective bores in the block.
5. An air-operated pump as set forth in claim 1 wherein said relay valve and power valve are movable in a generally vertical direction in said housing.
6. An air-operated pump as set forth in claim 1 wherein said head and said housing have mating generally planar faces.
7. An air-operated pump as set forth in claim 1 wherein said power valve comprises a perforated sleeve mounted in a bore in said housing, and a spool movable in said perforated sleeve.
8. An air-operated pump as set forth in claim 7 wherein said perforated sleeve has a plurality of circumferential rows of openings therein spaced at intervals along the sleeve.
9. An air-operated pump as set forth in claim 1 wherein said air signal valves, relay valve and power valve move along generally parallel axes.
10. An air-operated pump as set forth in claim 9 wherein said axes are generally vertical when the pump is operational.
11. An air-operated pump as set forth in claim 1 wherein said housing comprises a solid one-piece monolithic rectangular block having bores therein for receiving said air signal valves, relay valve and power valve, and removable covers fastened to said block for closing the ends of said bores.
12. An air-operated pump for pumping material, particularly a lubricant such as oil or grease, said pump comprising:
- a head comprising a cylinder;
- a piston reciprocal up and down in the cylinder;
- a pump plunger extending down from the piston, said plunger having an upper end connected to the piston and a lower end; and
- an air motor module for supplying air under pressure to the head for reciprocating the piston in the cylinder to move said pump plunger up and down through pumping strokes;
- said air motor module comprising a housing at one side of the head, said housing comprising a solid one-piece monolithic rectangular block, an air valve system in the housing for supplying air under pressure to the head for reciprocating the piston in the cylinder, said air valve system comprising air signal valves, a relay valve and a power valve received in respective recesses in said block, and one or more fasteners for securing the block to the head such that the module may be removed as a unit from the head.
13. An air-operated pump as set forth in claim 12 wherein said head and said block have mating generally planar faces.
14. An air-operated pump as set forth in claim 12 wherein said housing further comprises at least one removable cover closing respective ends of said recesses.
15. An air-operated pump as set forth in claim 12 wherein said recesses comprise vertical bores in said block, and wherein said at least one removable cover comprises a pair of removable covers for closing opposite ends of the bores.
16. An air-operated pump as set forth in claim 12 wherein said power valve comprises a perforated sleeve mounted in a respective bore in said block, and a spool movable in said perforated sleeve.
17. An air-operated pump as set forth in claim 16 wherein said perforated sleeve has a plurality of circumferential rows of openings therein spaced at intervals along the sleeve.
18. An air-operated pump as set forth in claim 12 wherein said air signal valves, relay valve and power valve move along generally parallel axes.
19. An air-operated pump as set forth in claim 18 wherein said axes are generally vertical when the pump is operational.
Type: Application
Filed: Mar 28, 2007
Publication Date: Oct 2, 2008
Applicant: LINCOLN INDUSTRIAL CORPORATION (St. Louis, MO)
Inventor: Thomas M. Arens (Florissant, MO)
Application Number: 11/692,242
International Classification: F04B 9/125 (20060101);