US3267866A - Electromagnetic oscillating-armature piston pump - Google Patents

Description

Aug. 23, 1966 L. UNGER 3,267,355

ELECTROMAGNETIC OS CILLATING-ARMATURE PISTON PUMP Filed Aug. 25, 1964 2 Sheets-Sheet l INVhNTOR.

LADISLAUS UNGLR.

ATTOIX LLIL Aug. 23, 1966 L.. UNGER 3,267,366

ELECTROMAGNETIC OSCILLATING-ARMATURE PISTON PUMP Filed Aug. 25, 1964 2 Sheets-Sheet 2.

FIG.2

INVENIOR.

LADIS LA US UNGILH.

ATTOhNLY.

United States Patent 3,267,866 ELECTRUMAGNETKC USCILLATENG-ARMATURE PISTON PUMP Ladislaus Unger, Malsch, Kreis Karlsruhe, Germany, assignor to Otto Eckerle Filed Aug. 25, 1964, Ser. No. 392,012 12 Claims. (Cl. 10353) Yet another object is to provide a pump wherein the return spring operates for the dual purpose of returning the piston in retrograde movement and, concurrently positively checking over-stroke to prevent chatter, excessive noise, and to increase efiiciency.

Ancillary to the immediately foregoing object, it is a purpose to provide a piston pump of the type aforesaid wherein clearance between the piston and cylinder headv at the beginning of a working stroke can be held at a minimum, thus increasing the expansion ratio, the possible etfec-tive range of operating pressures, and reducing the overall size of the pump, for any given capacity.

A still further object is to provide a pump which, by reason of the construction features aforesaid, can be used as a vacuum pump.

Yet another object is to provide a pump which operates with small electric or hysteresis losses over a wide range of sizes and capacities.

Other objects and advantages of the invention will become clear to those skilled in the art, after a study of the following detailed description in connection with the acc-ompanying drawing.

In the drawing:

FIGURE 1 is an axial section through a pump embodying the invention; and

FIGURE 2 is a corresponding section through a modification.

Referring in detail to FIGURE 1, a relatively heavy support 12 with an integral central upward extension 14, has a housing 1 detachably secured to its under face, as by threads, not shown. The housing is shaped to accommodate with a smooth fit the core 2 of an electromagnet. The core is made up of a plurality of 'E-shaped laminations, it being noted that the central upward arm of the E is shorter than the right and left arms, as viewed upon the figure, to define a space 6. Winding 3 of the electromagnet is wound on a spool which fits the projection 5 and extends across space 6. Housing 1 is of somewhat greater vertical dimension than that of the electromagnet, to leave aspace which is occupied by a laminated yoke 4.

Housing '1, central arm 5 of core 2, yoke 4 and support 12 have central aligned passages such as 7 in arm 5, to receive with a smooth lit the pump cylinder 8. It is noted that this cylinder has an enlarged cylindrical upper end threaded into a corresponding recess in the under side of support 12. The bore of the cylinder is reduced in diameter about midway of its length to form a circular shoulder 8a, and again at its lower end to define a second circular shoulder 8b.

Piston 9, of magnetic material, has a smooth fit within cylinder 7, and is centrally bored to provide a passage .for fluid. The bore in piston 9 has a counterbore 9a ice opening through its top end. The bore has a thin metallic lining 9b which is headed over or flared at its top end to fit over the shoulder formed between the bore and counterbore. The lining is unitarily fixed with the piston, as by a press fit or sweating. The lower end of the lining projects a short distance below the piston. This projec tion has a flanged collar 18 journaled for rotation thereon.

At its upper end the counterbore in piston 9 is enlarged to form a shoulder on which is fixed, as by press fit, or soldering, a centrally-apertured valve seat 11. A helical coil compression spring is positioned within counterbore 9a and acts to urge disk valve 9d upwardly against its seat 11.

The lower end of the central bore in cylinder -8 is fitted with a sleeve 16 with central passageway 16a. The sleeve has a flange spaced slightly 'below its upper end. This flange is sized 'for a smooth fit within the lower reduced portion of the cylinder. The lower end of the sleeve is threaded as indicated at 17, to engage the threaded lower end of cylinder *8 and thus enable the compression of an O-ring seal between the shoulder 8b at the lower end of the cylinder and the shoulder formed by the flange 0f the sleeve. The projecting threaded end of the sleeve also provides a connection for an exhaust pipe, not shown.

Helical coil compression spring 10 is positively connected at its upper end with collar 18 and at its lower end with sleeve 16. The connections are conveniently effected by the formation of channels or coarse threads on the reduced collar and sleeve and which are threaded or forced into the respective ends of the spring. The spring is so formed that in the position shown upon the figure, it is substantially unstressed but, of course, becomes compressed upon downward movement of piston 9. On the other hand, when the piston rises above the position shown, the spring becomes tensioned and thus acts to check motion of the piston into contact with the suction valve above. of the piston is prevented from overstroke and striking the suction valve, at the end of the retrograde stroke. The clearance may be kept at a minimum so that the expansion ratio may be relatively large.

The central bore in support 12 forms a short upward continuation of the same diameter as the contiguous end of cylinder 8. The bore is then reduced in diameter at 23 and finally expands into an internally threaded connection for an inlet pipe, not shown, from a source of fluid to be pumped. The reduced portion of the bore is threaded to take a short section of tubing or cage having a flange 22 seated against the downwardly-facing shoulder formed by the upper end of the cylinder bore. The lower end of this tube forms a downwardly-facing seat for a disk suction valve 13. A tension coil spring 21 has its respective ends connected with valve 13 and an anchor bar 21a fixed with and extending diametrically across the upper end of the tube, to thereby urge valve 13 onto its seat. Downward movement of the piston is limited by engagement between the flange of collar 18 and shoulder 8a. Since collar 18 is journaled on tube 9b, the piston may rotate in the cylinder without unscrewing the spring.

The operation will be clear from the foregoing description. Piston 9 is drawn downwardly in response to energization of the electromagnet and thus creates suction opening valve 13 and drawing a charge of fluid into the upper end of the cylinder. When the piston starts its return or working stroke under urge of spring 10, spring 21 closes valve 13, the trapped fluid forces valve 9d open and the fluid is forced downwardly to outlet or exhaust through passage 16a in sleeve 16.

The combined mass of the piston and parts carried thereby is relatively small so that the parts partaking of By this important feature the upper end take O-ring seals.

reciprocation do not necessarily have to be in resonance with the current energizing the electromagnet. The electrical losses are small, so that it is not necessary that such losses be recovered in part through the gain usually required and attained by reciprication in timed relation with the energizing current. Thus, as compared with prior art devices, the invention provides a much more versatile instrument and a wider range of pressures since the present pump is not restricted to the comparatively small resonance range.

It will be noted that by detaching plate or support 12 from housing 1, the entire assembly including the support, cylinder and all parts mounted therewithin may be removed as a unit. Thereafter, by unscrewing the cylinder from the support, the piston and valves are exposed for inspection and repair or replacement.

FIGURE 2 shows a modified form of the invention wherein the laminated core for the electromagnet comprises a lower E section 2' and an upper E section 2". The upper section is inverted so that the longer arms are in end-to-end contact and conjointly define slots lined with spool 28 about which winding or solenoid 3' is disposed. Since the central arms of both sections are shortened they define a space 6' between them.

The electromagnet thus formed is confined between top and bottom caps or plates 12' and 20, respectively. Top cap 12' has a central upper tubular projection threaded at 12a to receive connections, not shown, from a fluid supply, and a smaller downward tubular projection 12b sized for a smooth fit within and closing the upper end of cylinder 8. This cylinder, as shown, is a. plain thinwalled tube fitting a bore in the central arms of the core.

Lower cap 20 may be essentially a duplicate of cap 12', having a downward central tubular projection 20a threaded at 2012 for an outlet or exhaust coupling, not shown, and an upper central projection 19 smoothly fitting and closing the lower end of cylinder 8. As shown, both projections 12b and 19 are provided with channels to A sheath 29 'has its ends threaded or otherwise secured to and about the caps, to enclose the electromagnet.

Piston 9' has a smooth fit within cylinder 8. A central bore in the piston is lined with a thin-walled tube 30 which extends from the lower end of a counterbore 31 in the upper end of the piston, to a distance below the lower endthereof' The lower projecting end of tube 30 has a collar 18 journaled thereon and abutting the lower end of the piston. In the manner described previously for spring 10, FIGURE 1, a compression coil spring has its ends secured to collar 18' and projection 19 and is so constructed and arranged that in the position shown it is substantially unstressed and thus will act to retard further upward motion of the piston from the position shown.

An 'apertured valve seat disc 32 is fixed over the top end of piston 9. A coil spring 33 within counterbore 31 acts between the shoulder formed "by the lower end of the counterbore and valve disc 34 to urge the latter upwardly onto its seat on disc 32.

Lower projection 12b of upper cap 12' has been previously described. The central bore of this projection has a lining 35 fixed therein. The lining is flanged at its lower end to form a seat for suction valve 13 whose stem 27 projects upwardly through a guide 26 extending diametrically across and in fixed relation with the upper end of lining 35. A circular ledge 25 is fixed with the interior surface of the lining and forms an abutment for the lower end of a helical coil spring 24 surrounding stem 27 and at its upper or smaller end abutting -a small disc fixed to stem 27. Valve 13' is thus urged upwardly into contact with its seat on the flange of lining 35.

The operation of the modification of FIGURE 2 is basically like that previously described for FIGURE 1 so that further explanation is deemed unnecessary. Likewise this modification has similar advantages of ease of servicing and repair and usefulness over a wider range of pressures than prior art devices.

As one of the many possible variations of the invention it is contemplated that one or both of the outer arms of the E-shaped laminated core may be shortened and each provided with an additional pump unit which may be a duplicate of the one shown upon FIGURE 1 or that depicted in FIGURE 2. Also, by making the central arm of the core of sufficient size it may have two or more parallel axial bores or passages in each of which a pump unit as in FIGURES 1 and 2 will be mounted. In the case of two such units, for example, the pistons may work in opposite directions. That is to say, the cylinders will be in reversed positions and the working stroke of one piston will occur simultaneously with the suction stroke of the piston in the other cylinder. Also, the pump units may be connected for the pumping of fluid in series or in parallel, in the same direction of operation.

Numerous other modifications, and substitutions of equivalents, will occur to those skilled in the art, after a study of the foregoing disclosure. Hence the disclosure should be taken in an illustrative rather than a limiting sense; and it is my desire and intention to reserve all changes within the scope of the subjoined claims.

Although for convenience of description the terms downward, upward, etc., are used in the specification to describe the position of the parts as viewed upon the figures, it will be understood that the invention may be used in any angular position with respect to the vertical and horizontal, or inverted from the positions shown.

Having now fully disclosed the invention, what I claim and desire to secure by Letter Patent is:

1. In an electromagnetic piston pump, a cylinder having an inlet connection at its first end and an outlet connection at its second end, a piston of magnetic material slidably fitting said cylinder and having an axial passageway for fluid, a suction valve in said inlet connection and spring-urged to closed position, a pressure valve carried by said piston at the end thereof nearest said suction valve and spring-urged to closed position, a spring in said cylinder between the second end thereof and said piston, and urging the latter toward said first end of said cylinder, and electromagnetic means comprising a solenoid surrounding said cylinder, said piston forming the armature for said electromagnet, said spring being a coil spring compressed by motion of said piston in a suction stroke, and means positively connecting the respective ends of said spring with said piston and the second end of said cylinder, said spring being substantially unstressed when said piston is at its normal position spaced from the first end of said cylinder, and is under tension when the piston is displaced ztrom said normal position toward said first end whereby the motion of the piston is checked during operation to limit movement to a predetermined distance from said first end.

2. The pump of claim 1, said lastnamed means comprising a tube lining the axial passageway in said piston and projecting therefrom toward said spring, and a sleeve rotatably fittting about the projecting end of said tube and threaded into the contiguous end of said spring.

3. The pump of claim 2, there being a circular shoulder internally of said cylinder adjacent the second end thereof, said sleeve abutting said shoulder tolimit reciprocation of said piston in a suction stroke.

4. The pump of claim 1, said electromagnetic means including a E-shaped core having a central arm shorter than the end arms, said cylinder fitting an axial passage in said central arm, said solenoid being wound about said central arm.

5. The pump of claim 1, said electromagnetic means including first and second E-shaped cores each having a shortened central arm, said cores being reversed with their end arms aligned in end-to-end relation to define a space between the ends of said central arms, said cylinder extending through aligned axial passages in the central arms of said cores.

6. In a pump of the type described, a cylinder, a piston of magnetic material having a longitudinal bore for passage of fluid and slidable in said cylinder from a first position adjacent one end thereof, to a second position adjacent the other end thereof, a compression coil spring in said cylinder, and means fixing the respective ends of said spring to said piston and the other end of said cylinder said spring being under compression when the piston is at one of said positions and under tension when the piston is at the other of said positions whereby the tensional spring limits movement of the piston to a predetermined position.

7. The pump of claim 6, and spring-pressed pressure valve means carried by said piston at the fluid intake end thereof.

8. In an electromagnetically-operated piston pump, an E-shaped core having a central arm shorter than the outer arms of said core, a solenoid winding about said central arm, a yoke bridging the ends of said outer arms, there being aligned central apertures in and through said central arm and yoke, a cylinder fitting said apertures, a piston of magnetic material reciprocably fitting said cylinder and having an axial bore for passage of fluid, said bore being counterbored at its first end, an apertured valve plate secured over said first end of said piston, a valve disk in said counterbore, spring means in said countenbore urging said disk :into contact with said plate to close the aperture therein, and a coil spring connected at its respective ends with the second end of said piston and the adjacent end of said cylinder.

9. An electromagnetic piston pump comprising a support, a cylinder having its first end fixed to said support, there being 'an inlet passage in said support in axial alignment with said cylinder, a piston of magnetic material slidably fitting said cylinder, and having a longitudinal bore for passage of fluid thereth-rough, spring-closed pressure valve means carried by said piston to close said bore at the end thereof nearest said first end of said cylinder, a spring-closed suction valve over the opening of said passage into said cylinder, a spring in said cylinder between its second end and said piston, an E-shaped core of magnetizab le material having a shorter central arm, said cylinder fitting an axial passage in said central arm, a solenoid winding about said central arm, and means detachably securing said core and winding to said support.

10. The pump of claim 9, a tubular cage removab ly fitting the end of said inlet passage opening into said cylinder and forming a circular suction valve seat within said first end of said cylinder, a suction valve, and a spring connected at its respective end with said suction valve and a point in said cage remote from said piston. 11. In an electromagnetic piston pump, first and second E-shaped cores each having a shortened central arm, said cores being reversed and disposed with their end arms in aligned end-to-end contact, to define a space between said central arms, a solenoid winding enclosing both said central arms and space, said central arms having aligned axial passages, a cylinder fitting said passages and traversing said space, first and second end caps each having a projection fittting a respective end of said cylinder, means connecting said caps together to embrace said cores and cylinder between them, there being an intake passageway through said first cap and projection and an outlet passageway through said second cap and projection,

, a piston of magnetic material slidably fitting said cylinder opposite said space, and having a longitudinal bore for fluid, an apertured suction valve sea-t plate secured to said piston over the bore therein at the end adjacent said first cap, a first disk valve in said bore, spring means in said bore urging said disk valve into contact with said plate to close the aperture therein, a tubular cage removab ly fittting said intake passageway and forming an intake valve seat within the first end of said cylinder, a stem slidable in and along said cage, a second disk valve fixed with one end of said stem and movable therewith to seat on said intake valve seat, a spring in said tubular cage and engaging said stem to urge the valve thereof onto said intake valve seat, a coil spring in said cylinder and having its ends positively connected with said piston and said projection of said second cap, said spring being substantially unstressed when said piston is at the normal limit of its stroke toward said first cap, with said valves in spaced parallel relation.

12. An electromagnetic piston pump comprising, a support plate having an inlet passage therethrou-gh, a cylinder having a first end in fluid-tight communication with said passage, a piston of magnetic material slidably fitting said cylinder .and having a longitudinal :bore therethrough, apertured valve seat means secured over the end of said piston bore at the end nearest said passage, a valve in said here and spring-urged into position sealing the aperture in said valve seat means, said passage having a valve seat about its opening into said cylinder, a disk valve, a valve spring having one end connected to said disk valve on the side thereof remote from said piston, and means anchoring the other end of said valve spring at a point within said passage.

References Cited by the Examiner UNITED STATES PATENTS 2,488,384 [11/ 1949 Dickey et al. 2,801,591 8/1957 Parker 10353 X 3,194,162 7/1965 Williams 103-53 X OTHER REFERENCES German application 1,101,960, February 1957.

ROBERT M. WALKER, Primary Examiner.

Claims (1)

1. IN AN ELECTROMAGNETIC PISTON PUMP, A CYLINDER HAVING AN INLET CONNECTION AT ITS FIRST END AND AN OUTLET CONNECTION AT ITS SECOND END, A PISTON OF MAGNETIC MATERIAL SLIDABLY FITTING SAID CYLINDER AND HAVING AN AXIAL PASSAGEWAY FOR FLUID, A SUCTION VALVE IN SAID INLET CONNECTION AND SPRING-URGED TO CLOSED POSITION, A PRESSURE VALVE CARRIED BY SAID PISTON AT THE END THEREOF NEAREAST SAID SUCTION VALVE AND SPRING-URGED TO CLOSED POSITION, A SPRING IN SAID CYLINDER BETWEEN THE SECOND END THEREOF AND SAID PISTON, AND URGING THE LATTER TOWARD SAID FIRST END OF SAID CYLINDER, AND ELECTROMAGNETIC MEANS COMPRISING A SOLENOID SURROUNDING SAID CYLINDER, SAID PISTON FORMING THE ARMATURE FOR SAID ELECTROMAGNET, SAID SPRING BEING A COIL SPRING COMPRESSED BY MOTION OF SAID PISTON IN A SUCTION STROKE,

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