US 3130333 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
April 1964 R. J. FREYE ELECTRIC PUMP MOTOR 3 Sheets-Sheet 1 Filed May 17, 1961 INVENTOR.
ROBERT J. FAt'YE' BY W April 1964 R. J. FREYE ELECTRIC PUMP MOTOR 3 Sheets-Sheet 2 Filed May 17, 1961 INVENTOR. Ralf/P7 J'Z FRfYE A TTOR/Vl VS April 21, 1964 R J, EYE 3,130,333
ELECTRIC PUMP MOTOR Filed May 17, 1961 5 Sheets-Sheet 3 INVEN TOR.
ROBA'RT J: FRY
United States Patent Office 3,130,333 ELECTRIC PUMP MOTUR Robert J. Freye, Cass City, Mich, assignor to Walbro Corporation, Cass City, Mich, a corporation of Michigan Filed May 17, 1961, Ser. No. 110,771 5 Claims. (Cl. 310-48) This invention relates to an electric pump and more particularly to that type of pump which is utilized for the pumping of fuel to an internal combustion engine. The pump is an electromagnetic or solenoid-actuated device in which the switch mechanism is entirely self-contained within the pump housing.
It is an object of the invention to provide a pump of the type described for use on small gasoline engines such as outboard engines, compact car engines and small tractor engines, for example.
It is the purpose to provide a quiet operating pump which will have a capacity of from 15-30 gallons per hour.
It is a further object of the invention to provide a pump which is easily assembled and readily serviced in the event of need for repair.
Another object of the invention is the provision of a free armature mechanism which can find its own most efiicient operating position. The armature material that is used frequently has different flux patterns in different portions of the armature and with this arrangement it has been found that a fixed armature pump frequently has a tendency to develop torque or twist in the armature and thus dissipate some of the potential magnetic force' as well as cause cocking and binding of the armature in its movement. With the present design the armature is free to find its own eificient operating position and remain there without putting a strain on any of the parts. This type of construction has been found to produce a quieter pump which can reach an at rest position when there is no call for fuel without chattering.
The pump design results in less than one-half of the parts presently used for a similar pump and thus provides a less expensive pump. In addition, due to the fact that a longer spring can be utilized for the return function, the spring calibration is no longer critical.
Other objects and features of the invention relating to details of construction and operation will be apparent in the following description and claims.
Drawings accompany the disclosure and the various views thereof may be briefly described as follows:
FIGURE 1, a vertical section through the pump showing the relationship of the parts.
FIGURE 2, a top view of the pump housing.
FIGURE 3, a sectional view of the pump housing showing the switch parts taken on line 33 of FIGURE 1.
FIGURE 4, a cut-away view of the lower portion of the pump rotated 90 from the view of FIGURE 1.
FIGURE 5, a sectional View of a modified construction of pump armature.
Referring to the drawings:
'In FIGURE 1 a pump housing 20 has an inlet 22 and an outlet 24 connected by a pumping chamber 26 which opens to the inlet through a unidirectional valve 28 of conventional construction and opens to the outlet 24 through a unidirectional valve 30 of similar construction. The chamber 26 has a bottom opening 32 which registers with the top of a bellows type diaphragm 34. An annular edge 36 of the diaphragm is confined between an apertured plate 38 and the lower annular rim of the opening 32. A non-magnetic shell-type housing 40 depends from the housing 20, being fastened thereto by screws 42 shown in FIGURE 4.
The solenoid winding is mounted in this shell 40 by a mounting plate 44 held by screws 46 entering the bottom of the shell 40. The solenoid winding consists of an outer sheath 48, a winding 50 between plates 52 and 54, and a core member 56 having a top central bore 58. The armature of the solenoid is composed of a shaft 60 having a head portion 62 in bore 58 and a stud portion 64. Around the stud portion and mounted thereon above the head portion 62 is a circular plate 66 formed of magnetic material held on by a fastener 68. The stud portion of the armature passes through a perforated bottom 70 of the bellows 34 and has a sealing relation therewith. The bellows is preferably formed of a flexible material having a high life characteristic with an inherent resistance to liquid carbon fuels.
The mechanism for switching the solenoid is shown in FIGURES 1, 3 and 4. The power contact is made through a connector insulated from the housing 40 and having an electrical conductive relationship with a U-shaped conductor 82 (FIG. 1) fastened to the bottom of the solenoid. This conductor is connected through a lead wire 84 to one lead of the solenoid. The other lead 86 of the solenoid is connected to a leaf conductor 88 which is U-shaped in plan as shown in FIGURE 3 having the looped portions 90 extending downwardly.
The plate 88 is suitably insulated from the conductor 82 by a non-conductive spacer and carries two contact points 92. The arms of the plate 88 straddle the center of the solenoid and armature shaft 66. A second contact plate 98 has arms 160 which are struck downwardly from the general plane of the plate each carrying a contact point 102 (see FIGURE 4). The central portion 164 of the plate 98 is actuated by the armature and bears against a shoulder at the bottom of the armature shaft 60. The armature shaft continues down in a depending stud member 106 which has a cap screw 108 thereon supporting a spring 110 urging the plate portion 104 against the shoulder of the armature shaft 60. The remaining portion of the plate 98 is supported by a bolt 112, the head of which is spaced downwardly from the plate, a spring 114 being interposed between the head of the screw and the plate 98. Thus, as shown in FIGURE 4 when the armature shaft 60 is down, the contacts 92 and 102 are positively separated. When the armature shaft rises, a spring force is exerted against the plate 98 which urges it upwardly so that the contacts 92 and 102 can meet.
Surrounding the shaft 60 is a return spring which acts upwardly on the head portion 62 of the armature. Thus, it will be seen that power sent through the post 80 will be transmitted through the contacts 92 and 102 ultimately through the housing which is mounted through supporting lugs 122 (FIGURE 2). This completes a power circuit through the solenoid which draws the plate 66 and the armature shaft 60 downwardly. This downward motion breaks the connection through the contacts 92-102, allowing the return springs to come into action so that the contacts are again closed and thus repetitive action continues.
The disc armature plate 66 preferably has a loose fit on the shaft 64 of the armature so that it is free to find a magnetically at rest position relative to the armature winding. This plate increases the armature force, and its freedom to find a balanced magnetic condition, reduces the torque on the armature and other resulting cocking forces which tend to cause undue wear and loss of power.
It will be noted that the entire armature assembly is supported by the shell 40 which can be readily removed for a replacement or a repair. The spring tensions of spring 110 can be adjusted through a hole 124 in the bottom of the shell 40, this hole being normally closed by a snap but-ton 126. The installation of the solenoid into Patented Apr. 21, 1 964.
the shell is simplified by the pressure contact between the conductor 82 and the post 80 which avoids the necessity of any wire contacts screwed on or soldered on.
A modified construction is shown in FIGURE wherein the housing 20 and the plate 38 are identical to the previous disclosure. The bellows-type diaphragm 1443 has a shorter length than the diaphragm of FIGURE 1, but otherwise it is clamped in place by the top flange 142 in the same manner and it has a perforated bottom Wall 144 which has a sealing relationship with a stud 145 held on by a small metal fastener 143. The solenoid itself is composed again of an outer sheath 150 with a bottom plate 152 and a top plate 154 on either side of the winding 156 which has a center sheath 158 and a guide sleeve 16% within the center sheath. 7
The solenoid armature consists of a more massive cylindrical slug 162 compared with the armature shaft of FIG- URE 1 and on the top of this armature 162 is a dishshaped armature mass 164 having a central opening around the stud 146 the opening being lined by a small flanged sleeve 166 having an opening slightly larger than the stud. Interposed between plate 154 and the top flange 168 of the armature 164 is a relatively large diameter coil spring 176 guided on the cup 164 which urges the flange 168 upwardly in a return force. As in the previous modification, the supplemental mass 164 has a rotatable or floating relationship to the central mass 162 so that it may find its own balanced or at rest position magnetically in the field of the solenoid.
The make and break circuit of this solenoid is very similar to the previous disclosure wherein the conductive post 189 has conductive con-tact with the U-shaped conductive leaf 182 electrically connected to one terminal of the solenoid winding. A plate 184 mounted on the bolt 186 which also mounts the leaf 182 carries two upper contacts and the plate 136 mounted around the threaded stud 188 on the solenoid 162 and also on the bolt 11% carries the lower contact points for the make and break circuit.
The operation of the embodiment of FIGURE 5 is identical with that of FIGURE 1. It has the advantage that the spring 171 being a large coil is more readily calibrated and is not subject to fine adjustment. the spring avoids any heat destruction and any small adjustments required on the contact points can again be accomplished through the opening 192 by movement of nut 194. The operation of the embodiment of FIGURE 5 has been accomplished with the use of 8 amperes power, the resulting pump pressure and volume being in excess of anything developed by previous structures for that amperage input. I
The stud 138 at the bottom of FIGURE 5 and also the shaft 102 at the bottom of FIGURE 4- is preferably formed of non-magnetic material to prevent flux build-up in this area. The plates 52 and 54 at the top of the solenoid winding can be a phenolic material. The sleeve 160 is preferably of brass with a .004 clearance on the radius between the sleeve and the armature mass 162. The winding in the embodiment shown in FIGURE 5 has operated successfully with No. 22 gauge copper wire having 636 turns, the wire being provided with an insulation coating and machine Wound. Both devices shown need have no positive seating, and particularly is this true in the embodiment of FIGURE 5 so that there is no noise involved in the operation, the solenoid coming down against the spring 170 and the contacts being released prior to any physical contact of the armature with the remainder of the structure. This creates sufficient flexibility in the device that in the event of pressure build-up the device will stop operating until there is a call for fuel.
The use of a bellows formed of a soft material as distinguished from metal overcomes the armature flutter The large size of which has been previously a problem in connection with metallic bellows. This also reduces the amperage load and results in longer coil life and automatic shut-off as Well as increased volume as a result of a greater stroke.
While reference may have been made throughout the specification and in the claims to vertical relative location of the parts for purposes of convenience, this does not preclude the operation of the pump in other positions if the nature of the installation requires it.
1. In a pump of the type having a pumping chamber provided with an inlet and an outlet and an expansible member associated with said chamber having one end afiixed adjacent said chamber and the other end movable, that improvement which comprises a solenoid actuator for said expansible member comprising a solenoid winding having an armature passage therethrough, an armature having an actuator shaft extending through said passage, an armature disc carried by said actuator shaft, said shaft having means thereon to locate said disc axially, said disc being freely rotatable relative to said shaft, and interposed between said shaft and the moving end of said expansible member, a housing mounting said solenoid winding, means for fastening said housing to said pumping chamber, said housing carrying switch means for effecting continuous operation of said solenoid upon the introduction of current to said solenoid winding.
2. In a pumping combination of the type having a pumping chamber with an inlet and an outlet and an expansible member associated with said chamber, the improvement of an actuating mechanism for said expansible member comprising a shell housing to be mounted adjacent said pumping chamber, a solenoid winding carried within said shell housing, switch means on said winding for making and breaking a circuit to said solenoid winding, an armature passing through said winding having at one end actuating means for said switch means, said armature comprising a central shaft and a radially extending member extending over said solenoid winding at one end thereof adjacent said expansible member, said radially extending member having a freely rotative relationship with respect to said shaft.
3. A device as defined in claim 2 including a conductive stud passing through said shell housing in insulated relation thereto, and a conductive spring connecting said stud to said winding in contact internally of said shell with said stud.
4. A device as defined in claim 2 in which the radially extending member comprises a dish-shaped element of magnetic material having an outwardly extending flange, a spring seated on said flange around the dished walls of said member and bearing at the other end against said solenoid winding.
5. A device as defined in claim 2 in which the switch means comprises a U-shaped element fastened on one side of the solenoid having the legs projecting toward the center and around the central shaft, a second U-shaped element mounted on the other side of said solenoid having legs extending toward the center astraddle of the central shaft overlying the legs of the first U-shaped element, each of said elements having contacts aligned to provide a make and break circuit connection, and means on said armature shaft for actuating one of said elements away from the other of said elements, one of said elements being mounted in a biased relationship relative to the other.
Budlane May 19, 1953 Boyd June 26, 1956