US2228714A - Pump - Google Patents

Description

Jan. 14, 1941.

S. WILTSE PUMP Filed June 11,A 1937 2 Sheets-Sheet l Jam/7er )M7/'Ja BY ATTORN.

Jan. 14, 1941. s WlLTsE 2,228,714

PUMP Filed June 11, 1937 2 Smets-sheet 2 Patented Jan. 14, 1941 man PUMP

Sumner Wiltse, Detroit, Mich.

Application June 11, 1937, Seria-1 N e. 147,595

7 Claims.

This invention relates to reciprocating pumps of the type having a delivery or outiow stroke actuated by a resilient member, such as a spring, and a suction stroke induced against the action of said resilient member by an actuating unit receiving its power from some outside source. Such pumps are particularly adapted for use in pumping fuel for internal combustion engines since the spring actuated outflow stroke renders the pump automatically operable in proportion to the demand for fuel.

The greater number of present day pumps used in automobile practice are mechanically driven from some rotating part of the motor and, therefore, operate' at a speed proportional to that of the motor. It is true, however, that the speed of the motor is not necessarily properly controlling for the speed of the pump and often the speed is too great, pumping fuel at a rate which is not required and resulting in overheating of the pumped fuel with consequent loss thereof by evaporation.

The use of a reciprocating pump having a spring actuated outflow stroke results in automatically reducing the action of the pump when the amount of fuel delivered exceeds requirements, since when the pressure built up in the outflow line exceeds the spring pressure the pump will no longer reciprocate. However to gain full advantage from the use of this type of pump it is important that sufficient capacity be available for peak requirements and at the same time avoid pulsating now. This object, however, cannot be satisfactorily obtained by merely increasing the 1:5 size of one reciprocating unit to increase capacity.

It is, therefore, a primary object of the present invention to provide a pump having a primary pumping element with an outflow stroke so actuated as to be resiliently responsive to outflow pressure as aforesaid, but having the added feature of a secondary pumping element controlled in its reciprocation by the primary pumping element vbut alternating in suction and delivery strokes whereby a more nearly constant flow may be maintained at peak requirements while maintaining a practical rate of reciprocation for both pumping elements.

As one .possible embodiment it is a further object to provide fuel pump for internal combustion engines with primary and secondary reciprocating elements of the aforementionedcharacter having their suction strokes induced by a source of suction made available by other means associated with the engine such for instance as (CL 10S- 152) operating in proportion to the amount of fuel 10 required. i

It is another objectto make available a reciprocating pump having dual pumping elements having suction strokes induced by suction and delivery or outow strokes induced by spring 1.5

pressure or other resilient means, said elements being alternately connected to atmosphere and to a source of suction by Valve means operated by the movement of one of said pumping elements. 2o

It is a further object to provide a pump with dual pumping diaphragins, each of which is actuated in its pumping stroke by resilient means, such as a spring, and in its suction stroke by the operation of suction in a chamber provided on 25 the side of each diaphragm away from the fluid being pumped, the suction admitted to each chamber being controlled by a two way valve operated by the movement of one of the diaphragms. 3u

It is a further object to provide a duplex type of pump in which instead of employing a double acting cylinder and piston, the duplex function is performed by primary and secondary pumping elements but which are not physically intercon- 3 nected and having valve means for controlling the action of both pumping elements operated by the strokes of the primary pumping element.

The above and other objects of the invention will appear more fully from the following de- 4Q` tailed description of one possible mechanical embodiment of the invention which has been found satisfactory in actual operation, and by reference to the accompanying drawings forming a part hereof and wherein:

45 Fig. 1 is a vertical cross section through the pump showing the pumping chambers, the dual diaphragms, and the suction control valve.

Fig. 2 is a section taken on the line 2-2 of Fig. 1 and shows the inlet and outlet conduits 50 lthrough the two pumping chambers, together with the check valves required to effect the dual operation of the two pumping chambers.

Fig. 3 is a view taken substantially on the line 3 3 of Fig. 1 and shows a top view of the operat- 55 ing parts of the control valve for alternately connecting suction to the two diaphragms.

Fig. 4 is a section taken on the line 4-4 of Fig. 3 and shows a side view of the operating parts of the suction control valve.

Fig. 5 is a section taken on the line 5--5 of Fig. 4 and shows a cross section through the two valve units which control the alternate connection of suction and atmosphere with the two pumping chambers.

Fig. 6 shows a modified form of the pump in which an auxiliary manually operated mechanism is provided for alternately actuating the two pumping elements in a suction stroke.

Referring to the drawings, particularly .to Fig. 1, a central pump casting I0 preferably circular in shape is provided with an inlet conduit I I havin-gv suitable threaded connection flor a fuel pipe, not shown. 'Ilhis inlet conduit Il, in the form of a drilled hole, extends into the central portion of the pump casting I0 and communicates with two inlet check valves'designated generally by the reference characters I2 and I3, see Fig. 2, -through Isuitable cross-drilled conduits I4 and I5. The inlet check valve I2 communicates with a lower pumping chamber I6 formed byra recess in the lower face of the ycentral pump cas-ting I0; While the inlet check valve I3 communicates with an upper, pump chamber I1 formed by a similar recess in the top surface of the central pump casting I0. The communicating opening from the check valve I2 to the lo-wer pump chamber VI6 is shown Iat IB in Figs. 1 and 2, while the communicating :conduit to the upper pump chamber I1 is indicated by the full lines at I9 in Fig. 1. The above described sylstem of vides ya common inlet into the casting I0 with separate clieck valves I2 and I3 opening into the pump chambers I6 and I1 respectively.

The detailed construction of both check valves I2 and I3 is similar, as shown in Fig. 2, there being a specially designedvscrew 2l with a projecting end 22 for retaining a spring 23 which hold's a valve member 24 against a seat formed at the eind of each o-f the conduits I4 and I5. Provision for assembly of the check valves is accomplished by drilling from the outside of the casting l0 and providing suitable threads tlherein for the screws 2I.

There are 'separate` outlets for both 'pump chambers I6 and I1, the outlet from the lower pump' chamber I6 'being shown at 2-6 in Fig. 1 and' Fig. 2, and the outlet from the upper `pump chamber I1 being shown `dotted at 21 in Fig. 1. The conduit 26 leading from the lower pump chamber I6 :connects with the conduit 28 which leads into a main outlet conduit 29 extending across the casting ID and' shown in both Figs. 1 and 2. Another conduit 3I connects the conduit 21 from the upper pump chamber I1 with the main outlet conduit 29.- Outlet check valves 32 anjd 33 are provided for operation with the conduits 28 and3l respectively, thereby affording an outlet check valve from the upper and lower pump chambers into the main outlet conduit 29. Both outlet check valves 32 and 33 are of a construction similar to that used for the inlet check valves described above, a specially designed screw 34 with end projection 36, spring 31 and valve member 38 being pro-vided for each valve. The outlet conduit 29 has suitable threads at its end for connection of a fuel pipe, not shown.

A pumping diaphragm unit completes each of the pumping chambers I6 and I1, tlhe lower diaphragm being designated 'by the referenceV charfl-anges being designated as inlet conduits proacter 39 and the upper diaphragm by the reference .character 40. Each of these diaphragms is gripped between the flange formed on the edge of the central pump casting I0, and the iiange of a suction `and spring retaining chamber member 4I, for the lower pump chamber, and a similar member 42 for tlhe upper pump chamber, the

43 and 44 respectively. Suitable screw connecting means -are provided around the flanges 43 and 44 as indicated at 46 in Fig. 2. The lower ldiaphragm 39 has a stem 41 secured at its center by provision of two large washers 48 and 49 on opposite sides of the diaphragm 39, securely fastened by threads in the end of the stem 41 and by a nut 5I. The lower casting 4-I is of such shape as to form a chamber 52 and toretain a spring 53 therein. The stem 41 i's retained for reciprocating movement in a suitable guiding boss 54 extending into the chamber 52. One end of the spring 53 reacts against the lower end of the chamber 52 and the other end reacts against the washer 49 and tends to push the diaphragm 39 upwardly. The lower end of the stem 41 is mounted to reciprocate in a bearing 56 pro-vided in a lower cover member 51 'as shown in Fig. 1. A notch 58 is turned in the stem 41 for operating a valve mechanism which will later be described in detail. A valve chamber 59 is formed below chamber 52 and is connected therewith by an opening 6I. 'Ilhe valve chamber 59 is closed at its lower end by the lower 'cover member 51 in which there is mounted adual valve mechanism, as shown in Figs. 4 and 5.

Continuing with the vdescription of upper diaphragm 40 and its operating spring, the said diaphragm 40 is secured between the flange 44 of the casting 42 and the centr-al casting I9. A stem 62 is secured to the center of the diaphragm 40 by a pair of washers 63 and 64 on opposite sides of said diaphragm, the washers being held in place on the stem 62 by a suitable nut such as shbwn at 65. In a manner similar to that employed for the lower unit, the Istem 62 is mounted for reciprocating movement in a boss 66 extending downwardly into the upper diaphragm operating chamber 61 which is formed in the casting 42. As shown in Fig. 1, the chamber 61 is of such shape as to retainV a spring 68, one end of which reactsv against the upper end of the chamber land the opposite end reacts against the washer 64 and tends to force the diaphragm 40 downwardly. A conduit 13 leads from the lower valve unit to the chamber 61. It is lthrough this conduit that suction is p-rovided for the actuation ofthe upper pumping unit in a manner which will appear more fully later in this description.

The fitting 69 shown at the top of Fig. 1 is for the purpose of closing the opening provided for the reciprocating stem 62 and also when removed this member 69 serves as a handle ior manual operation of the top pump `chamber unit. The attachment of the handle is accomplished by threading the screw threaded end 1-I of fitting 69 into the opening 1l2 made avail-able when the fitting 69 .is removed. With the fitting 69 thus mounted a manual movement thereof in up and down `direction actuates the diaphragm 46 to manually operate the top half of the pump.

Proceeding now with the description of the two way valve unit shown in detail in Figs. 1, 3, 4 and 5, there is shown in Fig. 5 an opening at 14 for connecting a supply pipe from a source of suction. The drilled conduit 16, shown in Fig. 5, affords a communicating passage for the suction into chamber 59 when the valve positions are as shown in Fig. through the opening l1. The 1 andr 5. With the pump parts and toggle leveri necessary valve members are carried by plugs 8l, unit in the positions shown in Fig. 1, the valve S2 as shown in Fig. 5, threaded into the cover 5l' stems 83 and 8B will be held in the position shown by two threaded openings 18 and i9 provided in in Fig. 5 so that suction made available at 14 will 5 the 'cover 5l. The plug 8i has a valve seat proexhaust' air from the lower pump chamber 52 5 vided at each of its ends and carries a valve stem thru opening El', chamber 59, opening 'H and 83 with suitable valve closure members, 81! and 85 conduit 16. The lower pumping diaphragm 39 at its ends. The stem 83 is of sufiicient length is sho-wn at the beginning of its suction stroke in so that the distance between the `valve closure Fig. 1 and as the suction is applied in the cham- 10 members 8d and 35 is greater than the length of ber 52 the diaphragm 39 operates to perform its 10 the plug 8i Also the stem 83 is' of less diameter downward or suction stro-ke. The stem 41 is carthan the drilled opening 86 in the plug 8i, in ried with the diaphragm 39'and moves the toggle which the stem is slidably mounted. Radial ports member Si downward by contact with yoke |02, 86a (Fig. 4) connect drilled opening 36 with and near the end of the suction stroke the toggle A ODEP-ling i6 (Fig. 5) through annular Space Wb uni-t will snap to the opposite position. When 15 (Fig. 4). Therefore, when the valve member 83 this happens the position of member 96 will push. is in the upward position as shown in Fig. 5, the the valve stems 33 and 83 downwardly and will lower valve closure 84 is sealed while the upper' connect the suction at 'it thru conduits 76, 8T, closure is unsealed and the suction line is thus 93 and i3 to exhaust air from the upper pump allowed to communicate with the chamber 59' chamber 6l. At the same time change in the po- 20 through the opening Ti'. However, when the sition of closure member 9| at the end of stem 88 member e3 is in the downward position, the will connect chambers 59', 52 with atmospheric lower closure 8d is opened and the suction comchamber 82a thru conduit 90. munica-tes with conduit El below the valve plug It is understood that the reciprocation of the 2518i while the valve member S5 has closed the diaphragms 39 or liti, in their respective pumping 20 opening TI from communication with the `charnchambers i5 and Il', produces inflow of luid by ber 59. 'I'he other valve plug 82 shown in Fig. 5 action of the respective inlet check valves I2 and is similarly provided with a central hole 89 in i3 (Fig. 2) when the direction of movement of which the valve stem 83 reciprocates. A chamber said diaphragme 39 or @il is such as to increase '82a is form-ed between the lower face of the the volume of thechambers it or H. Conversely, 30 valve plug 82 and a closure plug 82h, this: chamwhen the direction of movement of the diaber Eid being open to the atmosphere thru a phragms 39 or 40 is in a direction to reduce the conduit 9d shown in Figs. 1 and 5. A valve volume of the pumping chambers i6 or I1, the closure member Si is secured at the end of the result will be an outflow of the iluid through the l stem S3 with surfaces so shaped that when stem outlet 29 by action of the respective outlet check 35 68 is in its downward position a conduit 89, leadvalves 32 and 33 (Fig. 2).

ing to chamber 5S, is open to the atmospheric It is apparent that the action of diaphragms chamber 3a while conduit 92 leading to upper 39 and 40 is alternating and the action of the dipump chamber 'i is closed. However, with the aphragm 40 is indirectly controlled by the move- 8S is closed and conduit 92 is ope-n to the atis directly attached. mospheric chamber 82a, thus supplying atmos- It is also to be noted that one -of the most impheric pressure to the upper pump chamber 6l portant advantages of this type of pump is that through conduits 93 and i3. Each of the valve the springs are acting against the resistance to stems 88 and 8S project upwardly as shown in outilow of the fluid being pumped. In other 40 Fis. 4 and are Connected together by a pin 2t, words, when the resistance to outflow becomes which proicots through a toggle lever member greater than the force exerted bythe spring 53 on 9S, as shown in Figs. 1, 3 and 4. Another toggle the lower pumping diaphragm the pump will no lever member Si' is mounted on a post QS, and longer exert a pumping stroke to force fluid into the two toggle members 95 and Si are operatively the line, In this manner the pumping actionis 50 Connected by a member 99 Which fits in JGWO momentarily stopped when the consumption of notches in their ends aS Shown in Fg- 1` The fuel is reduced and there is no continuous pumpmembers E36 and 9i are also Connected by a Spring ing with its attendant heating and evaporation of lili and are so positioned that movement of the the fuel such as occurs in many continuously re- *e* yoked end H32 of the toggle member Si will cause Ciprocai-,ing pumpe With the use, however, of a change in position of the member B6 from the they Combination of the upper diaphragm 40 upward location Shown in Fis- 1 to an opposite working alternately with the lower diaphragm 39 dovv'nWard DoStOl. This movement S a QUICK a suincient pumping ability isy assured at all times Snap When the toggle passes a demte point when a large quantity of fuel is required. This 60 (lo in its movement. It is understood that the yoke Cooperative alternating action is assured because i W2 ts around the notch 58 if the Stem SO that the action of the upper diaphragm is controlled dfwnward movement of the spem Q? .Wm will in its action by the lower diaphragm in such the toggle assume the opposite position to that manner that the upper pumping diaphragm is shown 1n Fig. l and close the valve i5 so that .h G5' suction is shut oif from the lower chambers 52 Opera'tufe to perfqrm a plfmpmg strek? While t e 65 and 59 and admitted to the upper, pump Chamber lower diaphragm 1s perfoimmg lts suction stroke. M It is also noted that atmospheric pressure is It 1s apparent that the use of double alternating admitted to the opposite chamber, not connected daphragms Controlled by one 0f them makes with the suction line, by the movement of the Practical the 115e 0f this WDG 0f Dump in many 70 valve stem 88 also actuated by the toggle Q6. conditions of operation requiring a considerable t0. The manner in which the pump operates is as range of fuel consumption, since the `double follows: A line from some unit producing sucstroke assures a sufficient capacity to take care tion, such for instance, as described in my coof all demands While avoiding pulsating flow. pending application, Serial'No. 147,595, led June The modified form off pump shown in Fig. 6 is so valve stem Sli in its upward position, the conduit ment of diaphragm 39 to which the valve control 40 1l, 1937, is connected at 'lf3 as. shown in Figs.A provided with mechanism for manual operation m upwardly also 4.. in addition to the automatic operation which has been previously described. In this modification the invention is particularly adapted for use in aircraft work where it is often necessary to have a hand operated pump for supplying fuel because of the usual practice of running the motors entirely out of fuel at certain times to reduce re hazard. It is intended that the pump shown in Fig. 6 be located in or near the pilots compartment so that handle |25 will be in a convenient position for operation. The central pump casting |26 shown in Fig. 6 is of identical construction with the central pump casting shown on Fig. 1 of the drawings. In fact, the entire mechanism for automatic operation and the dual diaphragm construction is the same as in the pump shown in Fig. 1. However, there is added in the construction shown in Fig. 6 necessary connecting parts to secure a manual operatinglinkage, denoted generally by the reference character |21, to stems |28 and |29 which are connected to actuate with upper and lower pumping diaphragms |30 and |3| in a suction stroke. For the purpose of manually actuating the top of the diaphragm |30 a hollow shaft |32 is mounted to reciprocate in a suitable boss |33 projectingfrom the top of the pump and suitably threaded to receive a nut |34 adapted to retain conventional packing |35. The hollow shaft |32 projects above the nut |34 and is pivotally mounted to a lever |36, the end of which is secured to a link |31. The hollow shaft |32 fits over and surrounds the stem |28 which is connected to the upper diaphragm |30. A pin |38 is secured to the stem |28 and projects outwardly therefrom into slots |39 and |40 in the sides of the hollow shaft |32. It will be noted that this means of connection of the stem |28 to the hollow shaft enables the diaphragm |30 t0 be automatically reciprocated by the suction mechanism when the shaft |32 is in the position as shown in Fig. 6 since the relative position of the slot |40 and the pin |38 allows reciprocation of the stem |28. However, when the-lever |36 is pulled away from the pump, i. e. upwardly, as shown in Fig. 6, it will pull the diaphragm |30 against the action of the diaphragm spring which normally urges the pump in a direction for a delivery stroke. In other words, the actuation of the lever |36 provides manual means for producing a suction` stroke, the delivery strokes still being spring actuated as in automatic operation.

A similar connecting means for manual operation is provided at the lower side of the pump for connection to the stem |29 in the form of a hollow shaft |4|, a nut |42, a lever |43 and a link |44, a pin |45 secured to stem |29 being provided to operate in the slots |46 and |41. It is apparent that the actuation of the lever |43 away from the pump will effect a suction stroke of the diaphragm |3| against the delivery stroke spring as previously mentioned in connection with the upper diaphragm operating lever |36.

For the purpose of normally holding the levers |36 and |43 in the position nearest the pump so that the slots in the hollow shafts |32 and 4| will not interfere with automatic operation of the pump, a tension spring |48 is provided vto connect the two ends of the levers |36 and |43 and therefore to normally urge them toward each other thereby producing the desired position of the levers. 'For the purpose of providing mechanism for placing the pump in condition for manual operation a pair of links |49 and |50 are provided with a pivotal connection |5|, the combined lengths of the links |49 and |50 being greater than the distance between the ends of the levers |36 and |43 when in the position nearest the pump as held by the tension of spring |48. Therefore, when the handle |25 is pushed toward the pump as shown in Fig. 6 to straighten out the links |49 and |50 the result is to spread the ends of the levers |36 and |43 away from each other against the tension of the spring |48. The position of the slots in the hollow shafts |32 and |4| will then be such that up and down movement of the handle |25 will alternately actuate the diaphragms |30 and |3| in a suction stroke, the delivery stroke in each case being accomplished by the spring which normally operates the diaphragms in this stroke.

Although I have described my invention as applied to a particular illustrative combination found practical in actual use, it is apparent that various changes and modifications may be made withoutl departing from the fundamental principles herein disclosed. I do not desire to limit myself to the specific embodiments but rather to the scope of the following claims.

I claim:

1. In a suction operated pump, a primary pumping element, a secondary pumping element movable independently of said primary pumping element, a common inlet and a common outlet conduit for both of said pumping elements, a suction valve operated by said primary pumping element controlling alternate admission of suction to both elements through said conduits, and a second valve interconnected with said suction valve for controlling alternate admission of atmospheric pressure to said primary and secondary pumping elements.

2. In a, pump, a central pump casting having a recess on twosides thereof, inlet and outlet check valves mounted in said casting and connecting with said recesses, independently movable diaphragms covering each of said recesses to form two pumping chambers, members shaped to form suction chambers on the opposite side of said diaphragms from said recesses and attached to said central casting in a manner such 1 asto grip the edges of said diaphragms, springs mounted in said suction chambers to normally urge said diaphragms inwardly of said pumping chambers, conduit connections to said pumping chambers including an atmospheric vent and a suction connection to said chambers, and valve means to alternately .subject said suction chambers to said suction connection and to atmospheric pressure whereby said diaphragms are alternately flexed outwardly against the action of said springs to produce suction strokes in said pumping chambers.

3. In a pump, a pair of independently movable pumping elements, resilient means fo-r actuating said pumping elements for outflow strokes, suction operated means for actuating said pumping elements for suction strokes, conduit connections to said pumping elements including an atmospheric vent for each of said elements, a source of suction, a two way valve connected to be operated by movement of said pumping elements to alternately connect said source of suction with said pair of pumping elements through said conduit connections and to alternatels7 open said atmospheric vents thereby to produce alternate operation of said pumping elements.

4. In a pump, a reciprocable primary pumping element for a delivery or outflow stroke, suction operated mechanism for actuating said primary pumping element in a suction stroke against the action of said resilient means, a secondary reciprocable pumping element movable independently of said primary pumping element, conduit connections to each of said pumping elements including an atmospheric vent for each of said elements, and means under control of said primary pumping element to cause said suction operated mechanism to operate said secondary pumping element in `a suction stroke and to alternately subject said pumping elements to suction and atmospheric pressure through said conduit connections.

5. In a pump, a pair of independently movable pumping elements, suction operated means actuating said pumping elements for suction strokes, resilient means actuating said pumping elements for outo-W strokes, a source ofsuction, a member connected to lreciprocate with one of said pumping elements, a two-Way valve connected thereto, conduit connections to each of said pumping elements including an atmospheric vent for each of said elements from said two- Way valve to said suction operated pumping elements, a toggle for operating the said two-way valve, a projection from said toggle contacting said reciprocating member whereby said two-way valve is operated when said reciprocating member and said pumping element complete a predetermined stroke thereby to alternately operate said pair of suction operated pumping elements through said conduit connections and to alternately subject said pumping elements to atmospheric pressure thru said atmospheric vent.

6. In a pump la primary pumping element having a delivery stroke actuated by spring pressure, a housing around said pumping element forming a suction chamber, a source of suction, a valve member including an atmospheric vent for connecting said source of suction or atmospheric pressure to said suction chamber to operate said pump for a suction stroke against the action of said spring at'the end of said spring actuated delivery stroke, a secondary pumping element, movable independently of said primary pumping element, a housing around said secondary pumping element forming a suction mvv,

chamber, a Valve member including an atmospheric vent for connecting said secondary pumping element with said source ofv suction or atmospheric pressure to actuate said secondary pumping element in a suction stroke, a member actuated by said primary pumping element whereby said valve is actuated to connect said source of suction with said secondary pumping element at the end of the suction stroke of said primary pumping element. v

7. In apump of the type in which the delivery or outflow stroke is actuated by a spring `pressed element characterized by a primary pumping element and a secondary pumping element movable independently of said primary pumping element, said secondary pumping element alternately set in operation for a delivery stroke at the end of the delivery stroke of said primary pumping element, and mechanism comprising a member actuated by said primary pumping element for controllingthe operation of both of said elements.V

SUMNER WILTSE.

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