US2179925A - Pump - Google Patents

Description

E. W. DILG Nov. 14, 1939i PUMP Filed NOv. 22, 1935 Mw w W 5 WIM Patented Nov. 14, 1939 UNITED STATES PATENT OFFICE PUMP tion of Michigan Application November 22, 1935, Serial No. 51,008

9 Claims.

usage arises from the possible leakage of gasoline liquid or fumes from the pumping compartment to the arcing electrical units. It is a primary object of the present invention to prevent any access of fuel or fumes to any sparking units.

Another problem in this type of pump -is to maintain a uniform and certain length and duration of the magnetic suction stroke, as unless such a uniform length and steady character of stroke is maintained the pumping mechanism has a tendency to flutter and fail to operate. It is necessary to keep the electrical circuit controlling the magnetic unit closed for the duration of a fully completed suction stroke and then to open it positively. It is therefore an important object to provide a switch mechanism which will accomplish the making of the circuit at the end of the spring actuated delivery stroke andthe breaking of the circuit at the end of the suction stroke, thereby governing exactly the length and certainty of the aforementioned suction stroke.

, The pump herein shown and described is of thediaphragm type, and while the substitution of a metal bellows or other expansible unit is contemplated as a possible variation in construction, it is nevertheless an object to provide a construction such that the cloth type diaphragm found sojpractical and economical in mechanical pumps may also be practical for use in electrically operated units. For purposes of facility of assembly and service it is a further object to provide a separable construction for the reciprocating parts of the mechanism-in order that a unit, such as for instance the expansible pumping unit, may be disled for service without disturbing the assembly of other units. Y

The above and further objects will appear more fully from the following detailed description and by reference 'to the Aaccompanying drawiong, whereinrig. 1 is a vertical cross section of the assembled pump unit showing the inlet and outlet,.

and the pump chamber as well as the electromagnetic and switch mechanism;

Fig. 2 is a section taken on the line 2--2 of Fig. 1 and shows the top view of the switch mechamsm; 5

Fig. 3 is a section similar to Fig. 1 but includes only the switch section and shows said switch in the opposite position from that shown in Fig. l;

Fig. 4 is a section on line 4+4 of Fig. 1 and shows the inlet and the screen vprovided above 10 the filter bowl at the bottom of the pump;

Fig. 5 is a section on line 5-5 of Fig. 4 and shows the pump chamber aswell as the inlet and outlet check valves.

Referring now to the construction illustrated 15 in the drawing and shown particularly in Fig. 1, the pump construction selected for illustration is composed of three main portions, namely, a fuel unit casting Ill, an electro-magnetic unit 2li and a switch unit 30. The fuel unit casting I0 20 has an inlet II suitably threaded for a supply line fitting, not shown, and which inlet continues into a conduit `I2 which opens into a filter bowl I3 attached to the fuel unit casting I0 as shown at I4. Between the illter bowl I3 and the fuel unit 25 casting I0, there Ais provided a screen I6 and gasket which are clamped between the ange Il of the filter bowl I3 and a mating edge I8 on the fuel unit casting I0.

As shown in Fig. 5, a chamber I9 is enclosed 30 by the fuel unit 'casting IIJ shown here as above the screen I6 and from this chamber I9 there is provided an inlet passage 2| to a main pump chamber 22. An inlet check valve 23 comprising a valve disk 24 is located in the inlet passage 35 and is held against a seat 25 by a spring 26 supported on a pedestal 21. It will be noted that this check valve allows ow into but not out of the main pump chamber 22. As vshown in both Figs. 1 and 5 an outlet passage'28 leads from 40 the main pump chamber 22 and is provided with a check valve 29 which allows flo'w only outward from the main pump chamber. The check valve 29 is made up of parts similar to those of the inlet valve, i. e., valve disk 3I, seat 32, spring 45 33 and pedestal 34. The outlet passage 28 continues in a passage 35 which leads to an outlet 36 provided with threads for connection to a vfuel supply line, not shown.

Between the fuel unit casting I0 and the mag- 50 netic unit 20 there is a diaphragm 31 which closes one end of the pump chamber 22, and it 1 is .thereciprocating exure of this diaphragm which provides the necessary changes in the volurne of the pump chamber 22, to cause fuel to 55 a magnet stop member 4| and a shell member 42 with an annular flange 43 projecting into the electromagnet core toward the stop QI but affording a substantial gap therebetween.. The shell member 42 also serves tov clamp the main diaphragm 31 against the adjacent end ofthe fuel unit casting I0, a suitable gasket 44 being interposed between the parts I0 and 42.

A magnet plunger 45 preferably of cylindrical shape is secured to the main diaphragm 81 by a screw 46 and anged washer 41. The plunger 45 is of such size as to operate within the annular flange 43 of' shell member 42 with'ample clearance. I

The stop 4I of the magnetic unit is provided with a central opening 48 in the base of a cup shaped recess 49 in which is pressed felt packing 50 surrounding a switch shaft 5I which projects through the opening 48 and'merely rests or abuts against the plunger 45 so that the diaphragm 31 with the plunger 45 attached may be removed for service without disturbing the parts associated with the shaft 5I. A secondary diaphragm 52 is shown as located at the other end of the magnetic unit 20 and is secured at its center to the shaft 5I between a pair of flanged washers 53 and 54 clamped upon the diaphragm by means of screw 5|a and the shaft parts 5Ib and 5|c. The secondary diaphragm 52 is also clamped adjacent to its outer edgebetween the magnet stop N and a switch base member 55. The base member 55 affords a supporting base for the switch unit 30 and is preferably shaped at the center to form on the under side retain-- ing *lugs 56, 58a for one 'end of the delivery stroke actuating spring 51. The other end ,of spring 51 acts against the flanged washer 54 and thereby exerts pressure through the'shaft 5| and tends to urge the shaft and the main diaphragm 31 and secondary diaphragm 52 in a direction inI wardly of the pumping'chamber 22 to perform the delivery or outflow stroke of the pump as.

will presently be more fully described.

Consideration will now be given the detailed parts of the switch unit which are mounted upon the base member 55. A pair of brackets 59, 59a are formed on the base member 55 and support a swinging switch contact carrying member 80 pivoted on a pin 5| while a fixed switch contact carrying member 52 (see Figs. 1 and 2) is. secured tobase member 55 by, screws 55 and 68, insulating washers (not shown) being interposed between the member 82 and base member 55. Contact points 58 on the swinging switch contact carrying member 50 are held normally against contact'points 88 of xed member 52 by a spring 51. 'I'he swinging Switch contact carrying member 88 has two projecting arms 15 so shaped as to I4provides. pair of L-shaped ends 12, n as shown at 12 in Fig. 3. Pivotauy mounted on the pin 5I carried by brackets 58, 59a is an actuating arm 18 which has a hole 14 of such lsize as to fit loosely in slot 15 in the switch shaft 5I. It is apparent that the actuating arm 13 will be swung upon the pivot pin 6I- in'accordance with. the movements of the shaft 5| by the above described mechanism.` To the end of the actuating arm 13, two springs 15 and 11 are connected, with their opposite ends secured to a switch ilapper member 18, the inner end of which is held by said springs 18, 11 into the notch 82 of V-shaped bracket 18, the notch 82 at the point of'the V thus providing a pivoting point for the switch flapper member 18; stops 80 and 8i for limiting themovement of the ilapper 18 being provided adjacent the outer legs of the V-shaped brackets. The switch flap- `per member is preferably U-shaped, asfshown best in Fig. 2,so that there are projecting ends 88 and 84 adapted to contact the L-shaped ends 12, 12a respectively of theswdtch contact car-- rying member 80, as best shown in Fig. 3.

Considering Figs. 1 and 3 with the last described mechanism, it will be apparent that when the plunger 45 and switch shaft 5I start to move from the position shown in Fig. 1, the actuating arm 13 will be swung upon .its pivot to. move the springs 15 and 11 therewith and when the la-t. ter are sufliciently off center they will cause the switch apper member 18 to snap from the position shown in Fig. 1, i. e., resting against stop 8l, to the position-shown in Fig. 3, i. e., resting against the stop 80. When this snap over occurs, the ends of the switch flapper member 18 are caused to strike the L-shaped portions 12, 12a of the projecting arms 18 and 1l on the Swinging 'switch vcontact carrying member 65 and cause a'deilnite breaking of the contact points 58 away from 69, which were normally held in contact by the pressure of the spring 51.

-The switch unit 30 may be provided with a suitable cover or housing 85 secured to the cas- ,ing 88 by suitable means.

A suitable binding post 81 comprising a bolt 88 is secured to, but insulated from, the cover 85 by means of conventional fibre insulations 89 and 88 provided with conventional washers 9|,

as well as two nuts 94 and 95. A suitable electrical connection 95 to the magnet winding 40 is provided from the inner end of the binding post 81 as shown. AThe opposite end 92 of the magnet winding may be connected to the' insulated fixed switch contact carrying member 82 and thereby provide for carrying the circuit. from the winding 45 to the contact points 59 and therebyto the contact pointsl 58, when the switch unit is in the closed position, the remainder of the switcl unit being on the grounded side of the circuit. v

The operation of the device is as follows:

In the initial position of the parts as shown in Fig. lcwith the switch shaft 5I and the diaphragm 81 in the position they would occupy at the cxtremev limit of a pumping or delivery stroke. the switch will have just been actuated to'close the circuit to the magnet winding, the switch contacts 55 and 55 being held together by the action of thespring 51 upon the swinging switch contact carrying member 58 so that the electrical circuit will be closed to energize the electromaget winding 4II and will therefore exert a force upon the plunger 45 to move the same inwardly of the magnet coil in accordance with the well known operation lof devices of this character. As the plunger 45 moves, it carries with it the main diaphragm 31, the switch shaft 5| and all of the umts connected thereto. This means that the diaphragm 81 will move outwardly of the \pump chamber to cause a definite increase in the volume of said chamber 22 and vset up a been allowed to enter through the inlet Il and conduit I2, to be sucked through the Screen I6 into the chamber I9 and thence into the pump chamber 22 through the passage 2|, the check valve 23 in this passage opening automatically to allow such entry.

With the above described movement of the switch shaft 5I, the actuating arm 13 because of its engagement with the slot 15 in said switch 10 shait 5I is swung upon its pivot and as the shaft nears the end of its stroke, the position of the actuating arm 13 and springs 16, 11 will be sufiiciently past center to cause snap over of the switch flapper member 18 upon its fulcrumed 15 engagement with the notch 82 from a position against stop 8l to a position against stop 80.'.

During this change the ends 83, 84 of the flapper 18 will 'strike against the L-shaped portions 12, 12a of the switch contact carrying member 60 20 and thereby positively move the contact 68 out of engagement with contact 69. thus cutting off the electrical circuit to the magnet winding 40. When this occurs the spring 51 becomes operative to cause the switch shaft to be forced in a direction to perform a delivery stroke moving the plunger 45 and main diaphragm 31 also and decreasing the volume of the pump chamber 22, thus causing the fuel drawn therein b'y the preceding suction stroke to be forced out through outlet passage 28, through check valve unit 29. The fluid then ilows through the passage and out the outlet 36 into the supply line not shown. As the switch shaft 5l starts its delivery stroke, the actuating arm 13 moves with it and near 35' the end of the outflow stroke the flapper member 18 will snap over from position against stop 80 to position against stop 8|, thereby relieving the pressure at 12 and 12a which held the swinging contact carrying member 60 in its open circuit 40 position, shown in Fig. 3. This allows the spring 61 to again push the contacts 68 and 69 together and start the cycle all over again. It is important to'note that the construction of the switch and associated parts is such that the making of the circuit occurs only at a predetermined point in the delivery or outflow stroke and the breaking of the circuit occurs only at a predetermined point in the suction stroke, the making and breaking each being effected to prevent objectionable arcing, and the circuit being held definitely closed until the completion of a desired Ysuction-stroke and open until the completion of a desired pumping stroke, respectively.

In following through the above described cycle of operation it is to be remembered that the provision of a spring or other resilient means to actuate the pump for a delivery stroke makes it possible fo'r the pump to regulate itself to varying demand for fuel or other liquid pumped. This 50 comes about from the fact that when the pump has builtup a pressure in the supply line, i. e., the line connected to the outlet 35, the delivery strokeactuating spring 51 will move the main diaphragm 31 against the pressure in the supply line only when the pressure is less than that exerted by the spring. Therefore the' pump will cease operating when the pressure in the line builds up to an' amount in excess of the spring pressure. It will thus be apparent that the operation of the pump'rwill depend upon the demand for fluid at the place of use. While it is understood that the use of a pump with spring j actuated delivery stroke is not broadly new, how` ever, this feature combined with the switch and magnetic means herein disclosed providesan electrically operated pump which can be successfully used in a line whose demand for liquid may be greatly varying over a considerable period of time. 'I'his pump, so installed, will adapt itself to the maintenance of a predetermined pressure 5 in the line regardless of flow and will pump intermittently as required. Furthermore, it will use current only when actually effecting a suction stroke which is always a relatively quick one, while with small demand the delivery stroke may 10 be relativelyof long duration. This feature of using current only on the suction stroke is accomplished by the construction of the switch mechanism, since as long as the pressure in the line issufiicient to overcome the spring 51, the 15 shaft 5I will be held in a position such that the switch flapper member 18 will maintain the position shown in Fig. 3 therefore holding contact point 68 separated from point 69 and maintaining an open circuit. However, as soon as the line 20 pressure drops suiliciently to allow the diaphragm 31 and the shaft 5| to move toward the end of the delivery stroke, then the switch parts will snap over t'o the position shown in Fig. l, i. e., with switch contacts closed which immediately 25 completes the circuit to the magnetic unit and starts a suction stroke, at the completion of which the pump then performs a delivery stroke in accordance with the pressure in the supply line as previously described. 30

It is to be noted that the construction of the magnetic unit is such that the plunger 45 is moved inwardly of thei coil with a minimum. tendency to pull to one side or the other because of the inwardly projecting annular flange 43 on 35 the shell member 42. This flange provides for a small gap between itself and the stop 4I, which is not provided in the conventional plunger electromagnet between outer metal shell and stop. With the short stroke required for pumping ac- 40 tion the small gap is sufficient and the additional metal serves to straighten and concentrate the Amagnetic lines of force in the axial direction so that the tendency for` side pull on the plunger is reduced to a minimum. This feature is very 45 important with this type of pump since it overcomes necessity for elaborate bearings and allows the use of a cloth type diaphragm if desired, but if a markedside pull were present such a construction would be impossible.

Although a particular pump construction has been used to illustrate the principles of the invention, it is apparent that various changes and modications might be made without departing from the novel and basic features of construc- 5'5 tion which constitute-the invention. For instance, in order to make use of the sealed compartment with secondary diaphragm-and switch means illustrated, the position of said switch means relative to the magnetic unit and pumping 60 unit is not necessarily limited to that shown. Also the location of parts such as the'lter bowl and screen in the position shown, although considered a very practical construction, might not be combined with the pump lin all installations. 65 Other obvious variations and modifications will be apparent to those skilled in the art as indicated by the scope of the following claims.

I claim:

1. In an electrically operated pump comprising, a pumping unit, a switch unit for controlling said pumping unit and a switch .operating member movable with said pumping unit to control the strokes thereof, sealing means 'secured and movable with said switch operating member and 75 interposed between said switch unit and4 said pumping unit whereby said. switch unit is sealed against leakage from said pumping unit to said switch unit,

2. -In an electrically controlled pump, a pumping unit, a switch mechanism located'separate from said pumping unit, pump actuating means controlled by, said switch mechanism, a switch operating member movable with said pump actuating means, and sealingl means secured to and movable with saidswitch operating member and interposed between said switch unit and said pumping unit whereby said switch unit is sealed against liquid or fume leakage from said pumping unit to said switch unit.

3. In an electrically operated reciprocating pump, reciprocating electrical means for actuat-A ing said pump, a Aswitch unit for controlling the reciprocation of said electrical actuating means. a switch operating member mountedfor reciprocation with said pump. and a sealing diaphragm secured to said switch actuating member and interposed between said switch unitandsaid pump thereby to seal said switch unit against liquid 'or fume leakage from said pump.

4. In an electrically operated pump having a pumping unit, a magnetic unit and a switch unit for actuating and controlling said pumping unit, a main diaphragm for inducing pumping action which also forms a dividing wallbetween said pumping andV magnetic unit, and a secondary reciprocating diaphragm forming a dividing wall between said magnetic unit and said switch unit.

5. In an electrically operated reciprocating pump, electrical means for actuating said pump. a switch unit separate from said electrical means for controlling the actuation of said electrical means, amain pumping diaphragm forming a dividing wall between said pump and said electrical means and a secondary reciprocating diaphragm forming a-'dviding wall lbetween said switch unit and said electrical means.

6. A pump comprising, a head, inlet and outlet check valves for controlling iiow through -said head, a casing secured to one side of said head providing a compartment therein, magnetic means enclosed in said compartment, va reciprocating pumping element operated-by said mag netic means and cooperating with said inlet and outlet check valve for providing pumping action, a second casing secured to said rst meijltiuucdA casing providing a compartment therein, e1ectri cal switch means for controlling said magnetic means located in said compartment of said second casing, a member mounted for reciprocation withsaid pumping element for operating said switch means, and sealing means secured'to said member and between said casing members theretoseal said magnetic means from said electrical switch means.

s' 7. In an electrically operated pump, a main diaphragm the reciprocation of which induces a -suction stroke in one direction and a delivery or therefrom, means normally urging said plunger and said diaphragm in a direction to produce a delivery or outilow stroke of said pump, an electro-magnet winding providing power to actuate said plunger, switch means normally maintaining an electrical circuit through said winding to thereby actuate. said plunger and said main diaphragm to induce a suction stroke of said pump, a shaft movable with said. plunger and contacting said switch means to actuate the 'latter to open the'electrlcal circuit at the end of said suction stroke and means including a secondary sealing diaphragm secured to said shaft to form a compartment enclosing said switch means "to isolate said switch compartmentirom the other parts oi' the pump.

8. An electrically operated pump having a pump chamber, a pumping element located in said chamber, switch means for controlling the strokes ot said pumping element, sealing means for isolating, said switch means from said pump chamber, and a member secured toand extending'irough said sealing means from said switch means and making abutting contact with said pumping element, whereby said pumping element be disassembled without disturbing said switch means or said sealing means.

9. An electrically operated pump of the type employing a reciprocating pumping unit, a switch for controlling the strokes of said pumpingunit having arcing contact points, switch operating means movable with said pumping unit and operatively associated with said switch unit to operate thev latter at the ends of the reciprocations of said pump characterized by a member associated with said pumping unit to'reciprocate therewith and projecting toward said .switch unit, and sealing Y means secured to said member f or isolating said Witchl unit from said pumping unit to form a mdd-tight and fume-tight seal between' said vpumping unit and said switch unit.

EARL v v. Dina.

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