US2458770A

US2458770A - Electrically actuated pump

Info

Publication number: US2458770A
Application number: US646950A
Authority: US
Inventors: John W Dickey; Millard M Henry; Theodore K Riggen
Original assignee: Bendix Aviation Corp
Current assignee: Bendix Aviation Corp
Priority date: 1946-02-11
Filing date: 1946-02-11
Publication date: 1949-01-11
Anticipated expiration: 1966-01-11

Description

Jan. 11, 1949. w, DlcKEY r 2,458,770

ELECTRI CALL! ACTUATED PUMP Filed Feb. 11, 1946 3 Sheets-Sheet 1 M NH Ilium...

wmmn 1 Hm I INVENTOR.

am we?) WITNESS' [iv/2mm:

Jan. 11, 1949. J. w. DICKEY EIAL ELECTRICALLY AGTUATED PUMP 3 Sheets-Sheet 2 Filed Feb. 11, 1946 NEY WITNESS. m-

Jan; 11, 1949. J w, D|CKEY ET AL 2,458,770

ELECTRICALLY ACTUATED PUMP Filed Feb. 11, 1946 3 Sheets-Sheet 3 INVEN TOR.

WITNESS: 67217;. 37.22;: (7mm NEY' Patented Jan. 11, 1949 ELECTRICALLY ACTUATED PUMP John W. Dickey, Millard M. Henry, and Theodore K. Riggen, Elmira, N. Y., aasignorl to Bendix Aviation Corporation, Elmira Heights, N. Y., a corporation of Delaware Application February 11, 1946, Serial No. 648,950

4 Claims. (Cl. 172-128) The present invention relates to reciprocating electrical motors and more particularly to motors for actuating pumps to automatically maintain a supply of liquid under substantially uniform pressure irrespective of the quantity required, such as electrical energy for its operation.

traverses the piston.

burning or erosion of the contacts.

tacts.

which ing shown diagrammatically;

line 22 of Fig. 1;

stantially on the line 33 of Fig. 2;

permanent magnet; and

2 of hinge for the contact controlling mechanism. In Fig. 1 of the drawing, there is illustrated a cylindrical pump casing-l having a closure cap 2 fixed in its upper end as by brazing or welding, and a removable cap I fitted on its lower end with The casing member I is preferably com- An electromagnetic 5 fuel pumps for internal combustion engines. an interposed gasket 4, providing a fluid-tight It is an object of the present invention to pro- Joint. vide a novel pump motor of the above type which posed of magnetically permeable material such as is efilcient and reliable in operation while being soft iron, and a partition member I of similar simple and economical in construction. material is fixed therein by suitable means such It is another object to provide such a device as copper welding, the position of the partition which is so constructed that it requires very little being preferably determined by an internal rib 8 formed in the casing. A pump cylinder 1 of It is another object to provide such a device non-magnetic material such as brass or stainless incorporating a reciprocating piston of magnetic steel is mounted at its ends in the cap 2 and the material in which the actuation of the piston is partition 5 respectively, said cylinder. having controlled magnetically by means of fiux which preferably a light press fit in the cap and partition, and the joints being rendered fluid-tight It is another object to provide such a device by suitable means such as copper welding. incorporating contacts for controlling the actua- The annular chamber formed by the casing I, tion of the piston with means for preventing cap 2, partition 5, and cylinder 1 is preferably evacuated or charged with an atmosphere of an It is another object to provide such a device inert gas in order to prolong the life of the elecin which the control contacts are actuated by a trical elements housed therein. permanent magnet, and the piston is arranged The partition 5 is provided with an upwardly to move into and out of the field of the magnet extending sleeve portion 8 providing a lower magto thereby vary the reluctance of the fiux circuit. netic pole piece, and an upper pole piece is pro- It is another object to provide such a device vided by a collar member 8 of magnetic material in which the means for controlling the contacts having a press fit in the casing l and closely suris substantially balanced so as to be unaffected rounding the cylinder 1. by translational forces, and is actuated solely by coil il occupies the space between the pole pieces magnetic force in opening and closing the con- 8 and 9, whereby when the coil is energized, a

' magnetic circuit is provided comprising pole piece Further objects and advantages will be ap- 0, partition 5, casing i, pole piece 9, and the gap parent from the following description taken in between the

pole pieces

8 and 9 which is bridged connection with the accompanying drawings in by the pump cylinder 7.

The partition 8 is provided with a downwardly Fig, 1 is a vertical substantially mid-sectional extending sleeve portion i2 which is threaded inview of one preferred embodiment of the inventeriorly to receive a threaded inlet valve member tion, the electrical circuit connections thereof be- 40 II. The member i3 is provided with a vertical passage it having an enlarged valve chamber I! Fig. 2 is a section taken substantially on the extending into the lower end of the cylinder 1.

A valve seat i8 is formed at the bottom of the Fig. 3 isasectional detail showing the magnetic chamber II, and a check valve member i1 is means for controlling the contacts, taken sub- .slidably mounted in the chamber and normally held in engagement with the seat It by means of Fig. 4 is a sectional detail taken substantially a valve spring I! which is retained in the chamon the line i-l of Fig. 2, the flux circuit of the ber by means of a thimble I9 fixed in the upper control magnet being indicated by dotted lines; end thereofasindicated at 2|.

Fig. 5 is a view similar to Fig. 2 of an embodi- The inlet member i3 is provided with a plument of the invention showing a contact conrality of radial passages 22 communicating with trolling rocker actuated by a substantially cubical the interior passage l4 and opening out into the space surrounding the inlet member. The inlet Fig, 6 is a view similar to Fig. 5 of an embodimember is also provided with a cylindrical enment of the invention incorporating a spring type largement 23 having a shoulder 24; and a screen member is arranged to seat at its lower end on the enlargement 23 and at its upper end on a packing ring 25 pressed on the partition member 5, said screen member being maintained in position by the shoulder 24 of the inlet member. The lower end of the inlet member is tapped as shown at 21 for the reception of a stud 28 which clamps the cap 3 against the lower end of the casing i.

A cylindrical piston 25 of magnetic material is slidabiy mounted in the cylinder 1 and is provided with a passage 3| therethrough which is narrowed at its upper end to provide a shoulder 32. Said shoulder provides a seat for the upper end of a spring 33 which rests at'its lower end on the thimble i5 whereby the spring urges the piston toward the upper end of the cylinder 1. A valve seat 34 is formed on the upper end of the piston 25, and a valve member 35 is yieldingly pressed against the seat by a spring 35 which is retained by a thimble 31 fixed to the upper end of the piston as indicated at 35.

An inlet pipe fitting 39 is fixedly mounted in the lower part of the casing i in any suitable manner and arranged to receive a tube 4| communicating with a source of liquid to be pumped. A bame 42 is preferably fixed to the inside of the casing l in order to deflect the entering liquid downwardly, and peripherally, and thereby assist the deposit of any suspended foreign material in the bottom cap 3 of the casing. An outlet pipe fitting 43 is fixed in the upper end of the cylfnder 1 with any suitable form of fluid-tight connection and is arranged to receive a tube 44 communicating with the receptacle to be supplied by the pump.

Means for periodically energizing the electromagnet ll so as to cause actuation of the pump plunger 25 is provided comprising a bat tery 45 grounded at 45 and connected through a switch 41 and conductor 45 to a binding post 45 mounted in the casing l and suitably insulated therefrom. A conductor 51 connects the binding post to one terminal of the electromagnet H, and the other terminal of the electromagnet is connected by a conductor 52 to a contact 53 mounted on a bracket 54 but insulated therefrom as indicated at 55. A movable contact 55 is mounted on a spring arm 51 (Fig. 2) fixed as indicated at 55 to a rocker 59 rotatably mounted on a pin 5| projecting upwardly from the upper pole piece member 5. The rocker and consequently the contact 55 are preferably electrically grounded by suitable means such as a flexible connection 55. A block 52 of permanently magnetized material is attached to the rocker 59 as.

by means of a clampingscrew 53. The block 52 is shaped to conform to the adjacent exterior surface of the cylinder 1, and is so magnetized as to present one pole to said cylinder, while the opposite pole of the magnet faces the interior of the casing I. A spacer 54 of non-magnetic materiel is suitably afilxed to the interior of the casing I in position to limit the swinging movement of the magnet 52 and prevent its engagement with the interior of the casing. A weight member 55 is preferably attached to or formed as a part of the rocker 59 in position to balance the weight of the block magnet 52, and also to serve as an abutment for the contact spring arm 51 and thereby provide a positive means for disengaging the movable contact 55 from the stationary contact 53.

When the parts are in idle position, the spring 33 holds the piston 25 in the upper end of the cylinder 1 with the thimble 31 in engagement with the lower end of the outlet man; u or with an interposed cushioning block 55 of suitable material if deemed desirable. Since at this time the upper. end of the piston is in registry with the permanent magnet 52, the attraction oi. the magnet for the piston causes the magnet to be held against the surface of the cylinder that contact 55 is pressed into engagement with contact 53 as shown in Fig. 2. When the switch 41 is closed to place the pump in operation, current from the battery 45 traverses the electromagnet H and

contacts

53, 55, returning by way of the ground, so that the electromagnet is energized and draws the piston 29 downward ly. The liquid in the lower end of the cylinder 1 is thereby forced up through the piston 25 and check valve 35, 34 into the upper end of the cylinder. When the upper end of the piston passes out of the field of the permanent magnet 52, said magnet is no longer attracted toward the cylinder 1, and its attraction for the casing i causes it to move outwardly into engagement with the spacer 54, thus moving contact 55 out of engagement with contact 53, deenergizing the electromagnet. The spring 33 then moves the piston 25 upwardly, ejecting the liquid trapped above the piston through the outlet conduit 44, v

and drawing a charge of liquid into the lower end of the cylinder through the check valve l1, l5. As soon as the upper end of the piston approaches the permanent magnet 52, said magnet again moves the rocker 55 to close

contacts

55, 53, and repeat the operation which continues as long as the switch 41 is closed and there is a demand for fluid to be supplied through the conduit 44.

When the receptacle to be supplied is full, the back pressure of the liquid prevents the piston from rising, so thattthereafter the actuation of the piston occurs only asand when there is a demand for the fluid to be supplied.

In order to reduce sparking at the contacts 53. 55, a cylinder 55 of electrically conductive material such as copper is preferably placed'on the pump cylinder 1 between the

pole pieces

8 and 9.

.- Burning or erosion of said contacts is further inhibited by the inert atmosphere within the upper portion of the casing I, whereby eilicient operation of the pump over long periods of time is assured.

In Fig. 5 of the drawing, there is illustrated a modification of the control contact actuating means in which the permanent magnet is in the form of a solid block which requires no machining. As here shown, rocker 1| pivoted at 12 has a pole piece 15 conforming to the exterior of the cylinder 1, and a permanent magnet 14 of substantially cubical shape is clamped to the rocker by means of studs 15 and 15. An arm 1? fixed to the rocker 1| has attached thereto at 18 a contact spring arm 19 which carries at its free end the movable contact 8|. A spring 52, also attached to the arm 11 by the rivet 18, bears against the interior of the casing I and tends to move the contact 8! away from the fixed contact 53. The remaining parts of the structure here shown are the same as in the first embodiment of the invention described, and are similarly numbered. The operation is the same as previously set forth except that the arm 11 serves to positively break the contacts 8i, 53 when the spring 52 withdraws the pole shoe 13 from the cylinder 1. a

In Fig. 6 oi the drawing, a control magnet Si is mounted on a flexible hinge member 92 anchored at 93 to the upper pole member 9 01' the electromagnet' II, and a contact 94 is mounted on a spring arm 95 also fixed to the permanent magnet 9| in position to engage the fixed contact 53. "A block 96 of magnetic material such as iron is fixed on the inside of the casing in position to draw the magnet 9| away from cylinder 1, a pad 91 of suitable non-magnetic material suchas fibre being cemented on the block 96 to form a backstop for the magnet, and limit the opening of

contacts

94, 53. The remaining parts are the same as shown in Fig. 1 and are similarly numbered, and the operation of the device is substantially the same except that in this case the movement of the permanent magnet 9| in opening and closing the

contacts

94, 53,

is permitted by fiexure of the hinge 92 instead of by pivotal movement of a rocker.

Although certain embodiments of the invention have been shown and described in detail, it will be understood that other embodiments are possible and that changes may be made in the design and arrangement of the parts without departing from the spirit of the invention as defined in the claims appended hereto.

What is claimed is:

1. In an electrically actuated pump, a cylinder of non-magnetic material, a hollow piston of magnetic material slidable therein, a spring arranged to move the piston toward the discharge end of the cylinder, electromagnetic means adapted when energized to move the piston toward the inlet end of the cylinder, and contacts for controlling the energization of the electromagnetic means, one of said contacts being movable; means for moving said contact including a permanent magnet and mounting means therefor permitting movement thereof toward and away from the cylinder, the permanent magnet being so located near thedischarge end of the cylinder that the piston on its discharge stroke enters the field of the magnet and thereby causes the magnet to move in a direction to bring the movable contact into engagement with the 00-- operating contact; and magnetic means in the field of the permanent magnet so located that the attraction of the permanent magnet therefor causes the magnet to move in a direction to separate the movable contact from its cooperating contact when the piston is withdrawn from the influence of the magnet.

' in claim 3 2. An electrically actuated pump as set forth in claim lincluding further, a casing of magnetic material enclosing and sealing the actuating and controlling means for the piston in inert atmosphere while constituting means for conducting the flux of the electromagnet and the permanent magnet.

3. In an electrically actuated pump, a nonmagnetic cylinder, a magnetic piston reciprocable therein, an electromagnet for moving the piston toward the inlet end of the cylinder, means for energizing the electromagnet including a pair of contacts, means for opening and closing the contacts including a permanent magnet located adjacent the discharge end of the cylinder, 2. spring for moving the piston into the field of the permanent magnet whereby the mutual attraction moves the permanent magnet to close the contacts, and magnetic means adjacent the permanent magnet for moving it to open the contacts when the piston is withdrawn by the electromagnet from the field of the permanent magnet.

4. An electrically actuated pump as set forth including further, non-magnetic means for spacing the permanent magnet from the magnetic means for opening the contacts, so as to cause the effect of the piston on the permanent magnet to preponderate when the piston enters the field of the permanent magnet.

JOHN W. DICKEY. MILLARD M. HENRY. THEODORE K. RIGGEN.

REFERENCES crrnn The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 458,873 Van Depoele Sept. 1, 1891 1,598,792 Wallace Sept. 7, 1926 1,615,139 Rusdell Jan. 18, 1927 1,640,742 Wallace et a1 Aug. 30, 1927 1,690,348 Wallace Nov. 6, 1928 2,179,925 Dilg Nov. 14, 1939 2,322,913 Best et a1 June 29, 1943 2,381,650 Dick Aug. 7, 1945