US2872871A - High capacity fuel pump - Google Patents

Description

A'. C; ALLEN HIGH CAPACITY FUEL PUMP Feb. 1,0, 1959 Filed May 10, 1956 2 Sheets-Sheet l www hm @MN WN l!! ver Feb. lo, A .C ALLEN Y HIGH CAPACITY FUEL PUMP Filed May 10, 1956 2 Sheets-Sheet 2 m ff?? United States Patent "ice ltilGH CAPA'CH'IY FUEL PUMP Arthur C. Allen, Chicago, lib, assigner to Stewart-Warner Corporation, Chicago, Ill., a corporation of Virginia Application May 10, 1956, Serial No. 584,093

13 Claims. (Cl. 10S-37) The present invention relates to fuel pumps for carburetor type internal combustion engines and more particular ly to electric pumps for supplying fuel to the carburetors of automotive vehicle engines.

Une object of the invention is to provide for maintaining a continuously adequate supply of liquid fuel to the carburetor of a high powered automotive vehicle engine, for example, an improved electric fuel pump, self-controlled to operate only as necessary to maintain a limited back pressure onrthe pump and having exceptional operating eiciency that provides at once for very significant minim'mation of the size and weight of the pump and for strikingly sharp responsiveness of the pump to only a slight diminution in normal back pressure to pump fuel at a high rate sufficient to meet the requirements of even the most powerful engines used in automotive vehicles.

Another object is to provide an improved pump of the above character which has at once the pumping efiiciency recited in the-previous -o-bject and the capacity to eliciently strain foreign particles from the fuel flow through the pump in a manner which maintains the pumping eiiiciency unimpaired by even substantial accumulations of material strained from the fuel.

Another object is to provide for the utmost convenience in servicing the improved pump recited in the preceding objects.

A more specific object is to provide an improved pump of the character recited which has an even output pressure that can be readily adjusted to meet the uid pressure requirements of different carburetors.

A further object is to provide a high capacity, solenoid operated fuel pump which is exceptionally quite in operation.

Other objects and advantages will become apparent from the following description of the exemplaryform of the invention illustrated in the drawings, in which:

Figure 1 is a longitudinal sectional view of a pump embodying the invention;

Fig. 2 is a fragmentary plan view showing the fuel inlet portion of the pump body and illustrating diagrammatically the connection of the pump inlet to a fuel tank;

Fig. 3 is a fragmentary plan view showing the fuel outlet portion of the pump body and illustrating diagrammatically the connection of pump outlet to a carburetor;

Fig. 4 is a perspective View showing the pump plunger rotated 90"` with respect to its position shown in Fig. 1 and partially sectioned to reveal internal valve structure;

Fig. 5 is an internal end view taken from the line 5-5 of Fig. l;

Fig. 6 is a fragmentary detail view taken along the line 6 6 of Fig l;

Fig. 7 is a fragmentary sectional view taken along the line 7-'7 of Fig. l; and

Fig. 8 is a fragmentary plan view showing the control switch cover.

2,872,871 Patented Feb. 1o, 1959 As will presently appear, the structure of the pump embodying the present invention is integrated together in a unique manner which facilitates servicing of the pump by providing quick access to any structural component.

In the preferred form shown, the improved pump comprises a hollow elongated body itl molded integrally as a unitary aluminum casting and having an outer generally cylindrical shell (also denoted by the numeral 10). Convenient support for the pump is provided by a suitable mounting bracket l2 embracing the medial portion of the body lli and adapted for attachment to any suitable vehicle structure (not shown).

The body l0 includes a hollow cylindrical barrel element 14 concentric with the outer shell of the body and extending to the right, Fig. l, of the longitudinal center of the body. Radially spaced inwardly from the outer shell of the 'body itl, the barrel element 14 is supported by an annular web f6 extending radially inward from the outer body shell and merging with a medial segment of the 'barrel element. v

The pump is energized magnetically by a solenoid assembly 1S removably mounted within the central portion of the body lil. The solenoid assembly 18 encircles a cylindrical plunger guide tube Ztl which projects from the inner end of the barrel element i4 nearly to the opposite end of the body l0. The tube 2li is formed from brass or other suitable nonmagnetic material. The barrel element end of the guide tube 20 is flanged radially outward, as shown, and held firmly in a shallow counterbore 22 in the inner end of the barrel element 14 by an annular seal 24. The seal 2d is backed up by a circular gland 25 pressed into the counterbore 22 behind the seal.

The solenoid assembly 18 comprises a centrally bored flat disc 23 closely encircling the guide tube Ztl and abuttingly engaging the inner end Iof the barrel element i4, Proper orientation of the disc 28 around the tube Ztl is assured by a short locating pin 30 supported in the outer shell of the body lll to extend inwardly into a radial slot 32 in the periphery of the disc. The disc 28 is formed of magnetic material to become one element of a magnetic circuit around the assembly 18.

The outer periphery of the disc 28 lits within one end of a cylindrical insert 34 lining the outer shell of the body lll) from the disc 28 for a substantial distance toward the end of the body opposite the barrel element 14. Formed of magnetic material, the insert 34 provides an outer longitudinal continuation of the magnetic circuit from the disc 28.

Proper location of the magnetic insert 34 in the body 10 is facilitated by the locating pin Sil which extends through a short longitudinal slot 36 in the adjacent end of the insert.

The space between the insert 3d and the tube 20 forms an annular pocket which receives a solenoid .38 prewound on a spool all, dimensioned to have a close sliding lit around the tube 2li. Two lead wires 42, 44, Fig. 7, extend from the solenoid 38 past the disc 23 to connect with two terminal sockets 46, 48 attached to the side of the disc 28 opposite the solenoid.

The solenoid spool 40 is held firmly against the disc Z8 by a spring washer Sil, Fig. l, encircling the tube 20 at the end of the solenoid opposite the disc 28. From an inner peripheral edge which engages the solenoid spool 40, the spring washer 5t) is dished away from the solenoid 38 to engage the adjacent surface of a centrally bored retaining nut 52 which lits closely around the outer end of the tube Ztl. The outer periphery of theretainer 52 is threaded into a counterbore 54 formed in the body 10. and extending from the adjacent end of the body somewhat beyond the adjacent end of the insert 34.

A cylindrical gland skirt 60 integral with the outer marginal edge of the retainer 52 telescopes around the adjacent end of the insert 34 to abut against an annular seal 62 at the bottom of the counterbore 54.

The retainer 52 is formed from-rnagnetic material to provide a continuation of the magnetic solenoid circuit extending radially inward from'the adjacent end of the insert 34 to the tube 20. v

The guide tube provides support to a cylindrical pumping plunger 64 dimensioned to have a close sliding fit within the tube. Formed of magnetic material, the plunger 64 serves as a solenoid core which, upon energization of the solenoid 38, tends to seek a position along the axis of the solenoid which minimizes the reluctance of the magnetic circuit around the solenoid. This magnetic circuit extends through the retainer SZ, the insert 34, the disc 28, and the portion of the plunger 64 between the disc 28 and the retainer. Thus, upon energization of the solenoid 38, the plunger is magnetically urged longitudinally to telescope into the retainer 52, as well as into Vthe disc 28, to minimize the overall space and hence the magnetic reluctance between the plunger and the two magnetic elements formed by the disc 28 and the retainer 52.

The end of the tube 20 remote from the barrel element 14 is covered by an intake valve assembly 66 threadedinto an annular boss 68 formed on the side of the retainer 52 opposite the solenoid 38. The boss 68 encircles and extends somewhat beyond the adjacent end of the tube 20. As will presently appear, the intake valve assembly 66 together with the portion of the tube 20 between the valve assembly and the adjacent end of the plunger 64 define a pumping chamber 69 into which fuel is admitted through the valve assembly.

Structurally, the intake valve assembly 66 comprises a centrally bored gland nut 70 threaded into a counterbore 72 in the boss 68. The inner end of the nut 70 telescopes around the adjacent end of the tube 20 and compresses an annular seal 74 against the bottom of the counterbore 72, causing the seal to firmly engage the tube.

A counterbore 76 in the outer end of the gland nut 70 receives the radially outward extremities of a spring retaining spider 78. The central portion of the spider 78 is offset, as shown, along the axis of the tube 20 toward the plunger 64. The outer ends of the spider 78 are anchored in the counterbore 76 by a centrally bored annulus 80 pressed into the counterbore behind the spider.

The radially inward marginal edge of the annulus 80 facing the plunger 64 provides a seat 82 for a circular check valve disc 84 biased againstv the valve seat by a compression spring 86 inserted between the valve disc and the adjacent central portion of the spring retaining spider 78.

Collection of magnetic particles from fuel entering the central bore 88 in the annulus 80 is provi-ded for in an extremely simple manner. For this purpose a magnetic wire 90, Figs. 1 and 5, is shaped to embrace a boss 92 formed on the annulus 80 to encircle the outer end of the bore 88. Opposite ends 94, 96 of the wire 90 are turned into parallel spaced relation to each other to extend part across the bore 88. The wire 90 is permanently magnetized so that its opposite ends 94, 96 form pole pieces of opposite polarity which attract magnetic particles fromthe stream of fuel entering the bore 88.

The intake valve assembly 66, including the magnetized wire 90, can be demounted simply by unscrewing the nut 70 from the retainer boss 68. Removal of the intake valve assembly opens up the adjacent end of the tube 20 for convenient withdrawal of the plunger 64, which contains an internal valve of improved construction that will be described presently.

Normally, the plunger 64 is biased away from the intake valve assembly 66 to create a substantial gap along the axis of the tube 20 between the inner periphery of the magnetic circuit member 52 and the adjacent end'of the plunger. This biasing action is produced by a helical compression spring 98 seated at opposite ends against the spider 78 and the plunger 64. As will presently appear, the strength of the spring 98 is coordinated with the control structure used in the improved pump to provide exceptional operating efficiency.

Foreign particles are filtered from the fuel flow through the pump in an extremely efficient manner which avoids interference with the output eiciency of the pump even after the accumulation of matter filtered from the fuel has become substantial.

For this purpose a hollow cylindrical filter 100, Fig. l, having a diameter approximately equal to that of the solenoid assembly 18, is disposed in surrounding spaced relation to the intake valve assembly 66. One end of the lter 100 abuttingly engages the peripheral edge of the retainer 52. The other end of the filter 100 extends a substantial distance beyond both the body 10 and the intake valve assembly 66. A pressure disc 102 closes the projecting end of the filter 100.

The portion of the filter 100 projecting beyond thc body 10 is encased with a filter bonnet or bowl 104. A radial flange 106 on the body end of the bonnet 104 fitswithin a shallow counterbore 108 in the adjacent end of the body 10 containing a sealing gasket 110.

The bonnet 104 is releasably held firmly against the gasket 110 by means of a swingable bail 112 extending across the outer end of the bonnet and having opposite ends pivotally supported in diametrically opposed bores 114 and 116 formed in the adjacent marginal edge of the body 10. Pressure is applied from the center of the bail 112 to the center of the bonnet 104 by a screw assembly comprising an outwardly convex pressure cup 118 adapted to seat against the center of the bonnet 104, a threaded stem 120 projecting through the cup 118 to engage the bail, and a knurled pressure nut 122 threadedly receiving the stem 120 and abutting against the cup.

It will be noted that a protuberance 124 swaged inwardly from the center of the bonnet 104 engages the pressure disc 102 to apply sufficient longitudinal pressure to the filter 100 to form an effective seal around opposite ends of the filter.

To gain access to the filter 100 it is necessary merely to turn the nut 122 to release pressure on the bonnet 104, swing the bail 112 to one side, and remove the bonnet 104. The filter 100 can then be lifted off for replacement or to provide unobstructed access to the previously described internal components of the pump.

The filter 100 is completely surrounded by a fuel supply chamber 125 formed by cylindrical space between the filter and radially outward structure of the body 10 and the bonnet 104 and by space between the pressure disc 102 and the bonnet. Fuel is supplied to the chamber 125 through an inlet bore 127, Fig. 2, extending radially through the marginal edge of the body 10 which surrounds the body end of the filter 100. As illustrated diagrammatically in Fig. 2, the inlet bore 127 is connected to a suction line 129 extending to a fuel tank 131.

The very large cylindrical area of the porous filter 100 provides, in effect, for a free flow of fuel through the filter from the supply chamber 12S to the space around the inlet Valve 66. The differential pressure required to strain fuel through the filter at a high rate is not sufficient to produce any significant impairment of the operating efiiciency of the pump even though the overall accumulation on the filter of foreign material screened from the fuel has become substantial.

Energization of the solenoid 38 is controlled by a readily demountable snap switch assembly 126 supported on a cylindhical boss 128 integrally formed on and extending laterally from the outer shell of the body 10. As shown in Fig. l, the boss 128 is aligned along the longitudinal axis of the body 10 with the portion of the barrel element 14 extending inwardly from the web 16.

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Thesnapswitch 126 is controlled in `response to reverse movements of the pistons 64 by means of a generally vertical lever assembly 130.

The lever assembly 130 is centrally supported by a horizontal pivot pin 132 extending across the medial portion of a cartridge 134. The cartridge 134 is inserted through the centrally open boss 128 and seated against a gasket 136 encircling a radial bore 138 in the adjacent side of the barrel element 14. The cartridge 134 has an open outer end separated from an inwardly open inner end by a transverse annular diaphragm 14d substantially alined with the pivot pin 132. The diaphragm 14!) has an inner marginal edge sealed around the medial portion of the lever assembly 30 and an outer marginal edge firmly held and sealed against the outer shell of the cartridge 134.

The sealing diaphragm 140 is formed from a tough plastic material which is substantially unaffected by contact with automotive vehicle fuels and highly resistant to fatigue by flexure. A preferred material used for this purpose is tetrafluoroethylene available under the trade name Teflon from E. i. du Pont de Nemours 8: Co., Inc., Arlington, New Jersey.

The inner end of the lever assembly 13d extends into nn annular groove 142 recessed into the outer cylindrical surface of the adjacent end of the plunger 64. As shown, the groove 142 extends a substantial distance along the axis of the plunger 64 between an annular shoulder 144 and an annular abutment 146 on the extreme adjacent end of the plunger.

To soften the action of the abutments 144, 146 on the lever assembly 130, as this action is transmitted to the outer end of the lever assembly, the lever assembly is centrally connected together by a resilient coupling 148 which yieldably holds opposite ends of the lever assembly in a predetermined fixed relationship to each other while at th same time providing for limited bending of the lever assembly at the coupling.

vFrom the coupling 148, the lever assembly 130 pro jects outwardly through the bottom of a cup-shaped switch casing element 150 nested in the boss 128. Covered by a circular switch support plate 152, the outer end of the switch cup 150 is flanged radially outward. Axial pressure is applied to the outer periphery of the switch cup 150 through the annular marginal edge of the plate 152, which is engaged by an annular shoulder 156 on a quick disconnect cap 158 forming a domelike cover for the plate 152. The cap 158 is retained on the boss 12S by quick thread means. As shown in Fig. 8, a skirt 166 o-n the cap 150 telescopes around the boss 128 and defines two open ended helical slots 162 which receive two anchoring pins 164 projecting from opposite sides of the boss. it will be understood that the construction shown in Fig. 8 is duplicated on the other side of the boss 128 and cap 158.

lt is noteworthy that the switch actuating cartridge 134 is inserted through the boss 128 ahead of the covered cup 150 and held firmly against the seal 136 by pressure applied, as shown, through an annular washer 166 inserted between the outer end of the cartridge and the adjacent inner end of the cup.

Electric power for energizing the solenoid 3S is supplied through an insulated lead wire 170 adapted to interconnect with the positive terminal of a vehicle battery (hot shown). The wire 170 extends through a central opening 172 in the cap 164 to connect with a positive terminal post 174 supported at its outer end on the plate 152. As shown in Fig. 7, the terminal post 174 extends inwardly into the terminal clip 48, which is connected through the wire 44 to one end of the solenoid 38.

The other terminal clip 46, Fig. 7, connected to the opposite end of the solenoid 38, receives the inner end of a second terminal post 176 parallel to the post 174 and Supported at its outer end on the plate 152.

The terminal post 176 and hence the solenoid 38 is controllably grounded through the previously mentioned snap switch assembly 126. Since the speciiic construction of the switch assembly 126 can be varied by those skilled in the art, it need not be speciically described here. It is suicient to point out that the terminal post 176, Fig. 7, is connected to a pair of yieldably supported stationary contacts 17g, Fig. l. The contacts 178 oppose a coacting pair of yieldably supported, movable contacts 18d) grounded through the plate 152.

The contacts 180 are moved into and out of engagement with the contacts 178 by an over-center compression spring 132 acting between the contacts 180 and a swingable spring support element 184 extending downwardly from the plate 152. An apertured lug 186 on the spring support 184 receives the upper end of the lever assembly 130. The support element 184 is formed from an insulating material.

The lever assembly 13) moves the spring support element 184 through a dead center position 'between one eX- treme position in which the spring 182 biases the contacts 1S() into engagement with the contacts 178 and another extreme position in which the spring 1%2 biases the contacts 130 out of engagement with the contacts 178 to break the circuit through the solenoid 38.

The positional relationship o'r the parts is such that upon opening of the switch 126 to deenergize the solenoid 38 the spring 98 moves the plunger 64 to the right, Fig. l, to produce a substantial gap between the inner periphery of the circuit member 52 and the adjacent end of the plunger before the plunger shoulder 144 operates through the switch assembly 131i to close the switch. The solenoid assembly 18 then operates as described to magnetically move the plunger 64 in the opposite direction until the plunger shoulder 146 engage the lever 130 to effect opening ofthe switch 126 with a snap action. This deenergizes the solenoid 38 to continue reciprocation oi' the plunger.

Electrically energized reciprocation of the plunger 64 thus provided for is utilized to pump fuel from the pumping chamber 69 to a plenum chamber 192 formed at the right hand end of the plunger.

The plenum chamber 192 is dened within the intermediate portion of the barrel element 14. The lateral `bore 138 opening through the barrel element 14 is closed by the previously mentioned switch control cartridge 134. The end of the barrel element 14 opposite the plunger 64 is plugged by a fluid ow control assembly 194 to be described presently.

Reciprocation of the plunger 64 pumps iluid from the chamber 69 into the plenum chamber 192 through a cylindrical bore 196, Figs. l and 4, extending longitudinally through the plunger. The bore 196 contains a highly eiiicient check valve 193 which is practically silent in operation even when the plunger is reciprocating at a rapid rate to effect self priming of the pump.

Actually the cylindrical, plunger bore surface (also denoted by the numeral 196) forms a part of the valve 19S which seals the bore against reverse flow of iiuid. As shown in Figs. l and 4, sealing of the bore 196 against the reverse dow of fluid is effected by engagement with the bore surface of the semi-elliptical edges of a pair of flexible valve blades 206, 262. The base of each blade is just sufficiently lwide to extend transversely across the bore 196. As shown, each blade 213i?, 292 extends from its base toward the plenum chamber end of the bore 196 and has a length approxi-mately twice the diameter of the bore.

The bases of the two blades 209 and 292 are integrally joined together and clamped between two narrow, opposing supports 266 and 208 extending transversely across the bore 1%. The two supports 2ti6 and 20S join respectively at opposite ends with two clamping rings 210 and 212 inserted into a counterbore 214 in the intake valve end of the plunger 64. A cylindrical retaining ring 216 pressed into the counterbore 214 holds the rings rrnly in place against the bottom of the counterbore.

Both blades 200, 202 are formed from a single fiat section of a firm yet flexible plastic material, preferably tetrauoroethylene, which will be referred to by the pre` viously mentioned trade name Teonf l Integrally formed from the same piece of material, the blades 200 and 202 tend to straighten out with respect to each other to engage the marginal edge of each blade with the cylindrical bore surface 196. The semi-elliptical shaping of each blade permits the blade to remain substantially at while effecting an engagement between the marginal edge of the blade and the bore surface 196 which is continuous around the blade as it projects from its supported base. Moreover, the marginal edge of each blade-see, for example, the edge 218 of the blade 200, Fig. 4--is shaped to make surface rather than line contact with the bore surface 196.

In operation, only slight differential fluid pressure tending to produce fluid flow through the bore 196 toward the plenum chamber causes the two valve blades 200, 202 to swing together. This allows substantially unrestricted laminar flow of fluid through the bore. Resistance to the flow of fluid through the valve 198 is minimized not only by the large unobstructed flow areas around the supports 206, 208 and along the lblades but also by the fact that the fluid passes by the valve and through the bore 196 in a laminar flow pattern without changing direction.

Reverse fiow of tiuid through the bore 196 is prevented by the blades 200, 202 swinging outwardly to seal against the bore surface 196 in the manner described. Differential pressure tending to produce a reverse flow of uid past the valve serves to increase the pressure With which the edges ot' the blades 200, 202 are sealed against the bore surface.

Constructed in the manner described, the valve 198 is virtually soundless in operation.

This noiseless operation of the valve 198 is particularly significant in quieting operation of the pump even when the plunger 64 is reciprocated at the exceptionally high rates prevailing when the pump is pumping air and fuel vapor in a self-priming phase of its operation.

The free iiow characteristics of the unidirectional valve 198 facilitates quick movement of the plunger 64 toward the intake valve assembly 66 to successively recock the power spring 98. The ability of the plunger 64 to move quickly toward the intake valve is highly advantageous. lt minimizes the period during which the actuating solenoid 3S must be energized, with consequent reductions in the power consumption of the pump. Also, it minimizes interruption in the maintenance of normal pumping pressure in the plenum chamber 192.

The effective volumetric output of the pump from the pumping chamber 192 is controlled in accordance with the back pressure on the pump by means of a regulator, including the previously mentioned assembly 194, which serves the additional function of assuring an even pump output pressure that can be adjusted to different pressure levels to fulfill the fluid pressure requirements of different internal combustion engine carburetors.

The regulator valve assembly 194 operates to throttle fluid under pressure from the plenum chamber 192 into a discharge chamber 220 formed in the adjacent end of the body around and extending beyond the outer end of the barrel element 14. The outer end of the discharge chamber 224i is closed by a flexible diaphragm 222 also formed from tetrafluoroethylene. The peripheral edge of the diaphragm 222 is secured to the `adjacent marginal edge of the body 10 by the peripheral edge of a header disc 224 detachably secured to the body by screws 226. A11 outlet from the discharge chamber 220 is provided by a radial bore 228, Fig. 3, extending through the adjacent marginal edge of the body shell 10. As shown diagrammatically in Fig. 3, the bore 228 connects with a fuel line 229 extending to an internal combustion engine earburetor 231.

Structurally, the regulator valvei assembly 194 comprises an outwardly open cup 230, Figs. 1 and 6, threaded into the outer end of the barrel element 14. Two openings 232 in the bottom 234, Fig. 6, of the cup 230 provide communication between the pumping chamber 192 and the interior of the cup.

A centrally bored annulus 236 pressed into the outer end of the cup 230 defines an annular valve seat 238 opposing a circular valve member 240 urged toward the seat by a compression spring 242 supported by the cup bottom 234. A cylindrical skirt 244 on the valve member 240 encircles a cylindrical guide 246 staked to the cup bottom 234.

The inner diameter of the valve member skirt 244 is dimensioned to provide radial clearance around the cylindrical guide 246 just sufficient to provide an effective dashpot action which steadies movement of the valve member 240 toward and away from the seat 238.

The valve member 240 is moved away from the seat 238 against the spring 242 by means of a stem 248 cxtending from the valve member through the annulus 236 to engage the center of the diaphragm 222.

The central portion of the diaphragm 222 is backed up on the side opposite the valve assembly 194 by a circular support or pressure distribution head 250. A stem 252 fixed to the side of the pressure head 250 opposite the diaphragm 222 extends into a helical compression spring 254 seated Within an inwardly open bore 256 in a pressure regulating screw 258. The screw 258 is threaded into a central spud 259 on the header plate 224 and held in adjusted position by a locknut 260.

The pressure control spring 254 acts through the head 250 and diaphragm 222 to hold the valve member 240 in open position until the back pressure on the pump, i. e., the pressure within the discharge chamber 220, has reached a predetermined value sufficient to meet the fuel pressure requirements of the carburetor 231. When this back pressure, which is practically synonymous with the effective output pressure of the pump, reaches the predetermined value the pressure of fuel on the diaphragm 222 overcomes the force of the spring 254 allowing the spring 242 to move the valve member 240 toward the seat 238.

The back pressure required to effect closing of the regulating valve in this manner can be readily adjusted to meet the fuel pressure requirements of different carburetors by adjusting the threaded screw 253 to vary the residual stress in the spring 254.

it is significant that in addition to its function in serving as a control for the throttling valve member 240 the diaphragm 222 provides effective assurance of an even output pressure from the discharge chamber 220. Thus, as shown, the pressure head 250 terminates a substantial'distance radially inward of the adjacent marginal edge of the body 10, thus leaving an annular portion 262 of the diaphragm unsupported by the pressure head. Due to the flexibility of the material forming the diaphragm 222, the unsupported annular portion 262 pulsates to effectively suppress rapid pressure fluctuations which might otherwise occur in the discharge chamber 220. As a result, the output pressure from the chamber 220 is maintained at a substantially even level.

lt may be observed that the plunger 64 could have a tendency to over-travel when it is cycling at an accelerated rate during a pump priming phase of its operation. This is effectively controlled by means of a buffer spring 264, Fig. l, supported in a counterbore 266 in the plenum chamber end of the plunger 64 and projecting outwardly beyond the plunger to engage the bottom of the valve cup 230.

The improved pump thus formed has extraordinary efficiency in operation which provides not only for highly significant minimiation of'the size and weight of the pump structure but also for strikingly sharp responsiveness of the pump to only a slight diminution in the normal back pressure in the pump discharge chamber 220 to pump fuel at a high rate sutiicient to meet the requirements oi even the most powerful engines used in automotive vehicles. The automatically controlled throttling action of the regulator valve assembly 194 limits the pressure in the discharge chamber 220 to a predetermined value which can be tolerated by the carburetor 231, while at the same time providing for the use of a powerful plunger operating spring 93 that enables the pump to meet extremely high volumetric output requirements by means of pumping structure of reduced overall size and weight. The extraordinary responsiveness of the pumping action to even a slight diminution in the normal back pressure in the discharge chamber 220 is such that the discharge of fuel from the pump at a rate sufiicient to supply a carburetor of even the most powerful automotive vehicle engine does not result in an undesirable drop in pressure at the pump outlet 228, Fig. 3.

To briefly review the extraordinary serviceability of the pump thus provided, it will be appreciated that every major component of the pump is readily accessible for inspection or repair in the event this becomes desirable. The switch E26 can be quickly removed simply by turning the cap iSd to release the latter from the boss 128. After lifting the switch 126 and cup 15) out of the boss M3, the service man can lift out the lever 133 and cartridge 134.

Removal or" the screw attached header 224 provides free access not only to the diaphragm 222 and its spring support structure but, also, to the throttling valve assembly 194, which can be quickly unthreaded from the barrel element 14.

Turning of the nut 122 at the opposite end of the pump releases the bail 112 in the manner described, thus affording convenient access to the filter 160 and intake valve assembly 66. The assembly 66 can be screwed out orr the boss 68 to permit withdrawal of the spring 93 and plunger 64 if desired. Further, the rerainer 52 can be screwed out of the counterbore 54 to permit the remaining components of the solenoid assembly 18 to be slid off the tube 29 and out of the body 10.

The readiness with which access may be had to the component structure of the pump adds much in the way of the overall utility to the operational capabilities afforded by the invention.

l claim:

l. For supplying fuel to an internal combustion engine carburetor, a high capacity fuel pump comprising, in combination, a` reciprocable magnetic plunger, means including one end of said plunger defining a plenum chamber, means including the opposite end of said plunger defining a pumping chamber, means including a fuel intake check valve connected to supply fuel to said pumping chamber, a solenoid operating assembly including two spaced circuit members disposed in adjacent rela-tion to said plunger to urge the latter magnetically toward an overlapping position with respect to both circuit members, a powerful operating spring connected to said plunger to urge the latter away from said position in a direction for expanding said pumping chamber, said plunger defining a passageway extending therethrough between said pumping chamber and said plenum chamber, a check valve mounted on said plunger to prevent reverse tlow of liuid through said passageway toward the pumping chamber end thereof, electric power supply means connected to said solenoid assembly and mounted in association with said plunger to energize the solenoid assembly as an incident to predetermined spring produced movement of the plunger toward said plenum chamber and to deenergize the solenoid assembly as an incident to predetermined magnetically produced movement of the kplunger foward Seid pumping chamber, means d ening a fuel discharge chamber and including yieldable means preconditioned to move reversibly in response to changing iiuid pressure within the discharge chamber, a control valve connecting said plenum chamber to said discharge chamber, and means coacting with said control valve and with said yieldable discharge chamber defining means to effect closing of the control valve as an incident to movement of said yieldable means by an increase in pressure within said discharge chamber to a` predetermined value and to quickly open the control valve as an incident to movement of said yieldable means in response to a slight decrease in the discharge chamber pressure below said predetermined value.

2, For maintaining a continuously adequate supply of `fuel to a high powered internal combustion engine carburetor, a compact high capacity electric fuel pump comprising, in combination, a body including an elongated outer shell and a hollow barrel element generally concentric with the outer shell, a nonmagnetic guide tube projecting from one end of said barrel element generally along the axis of elongation of said body shell and dis posed substantially within said shell, a solenoid slidably encircling said tube, magnetic circuit means for said solenoid including two annular discs detachably encircling said tube at opposite ends of the solenoid, the disc remote from said barrel element forming a retainer detachably secured to said body shell, a fuel intake valve assembly threadedly secured in said retainer disc in covering relation to the adjacent end of said tube, a` magnetic plunger slidably disposed within said tube for recprocation therein, a strong power spring inserted between said intake valve assembly and the adjacent end of said plunger to urge the latter away from said retainer disc, said plunger defining a bore extending longitudinally therethrough, a check valve mounted on said plunger to prevent reverse iiow of fiuid through said plunger bore toward said intake valve assembly end thereof, said barrel element defining an opening in the side thereof, a switch actuating cartridge removably disposed in sealing relation to said opening and containing a. transverse sealing diaphragm in the cartridge, a switch actuating lever assembly pivotally supported on said cartridge and extending into coacting relation with the adjacent end of said plunger `for actuation by movement of the latter in opposite directions, said body shell defining a hollow `boss thereon aligned with said actuator cartridge to permit ready insertion and removal of the latter through the boss, a control switch assembly shaped to fit removably into said boss for coaction with said switch actuator, said switch assembly including terminal posts extending inwardly, terminal sockets connected with said solenoid and supported on said annular solenoid circuit disc adjacent said barrel element in position to re eive said terminal posts, a quick disconnect cap disposed in covering relation to said boss and shaped to apply retaining force to said switch assembly, a control valve assembly detachably secured in the end of said barrel element opposite said solenoid whereby said barrel element is closed oft to form a plenum chamber therein, means on said body adjacent said control valve cooperating with the body to define therewith a discharge chamber communicating with the downstream side of said control valve, said discharge chamber defining means including pressure responsive means positioned to operate in response to changes in fluid pressure within said discharge chamber, means coacting with said pressure responsive means and with said control Valve to close the latter automatically in respouse to a. buildup in pressure within said discharge chamber to a predetermined carburetor supplying level and to open said control valve automatically in response to a receding in the discharge chamber pressure below said level, and means defining an outlet from saidy discharge chamber.

3. For providing a high powered internal combustion engine carburetor with a continuously adequate supply 11 t Y of fuel under proper pressure, a compact high capacity fuel pump comprising, in combination, a reciprocable magnetic pump plunger, meansY supporting said plunger for recipi'ocation and forming an effective fluid seal therearound, means including one end of said plunger defining a plenum chamber, and means including the other end of said plunger Vdefining a pumping chamber', means including a fuel intake check valve connected to supply fuel to said pumping chamber, said plunger defining a bore extending therethrough between said pumping chamber and said plenum chamber, a check valve mounted on said plunger in position to automatically block fluid flow through said bore toward the pumping chamber end thereof, a strong power spring inter'- connected With said plunger to urge the latter in a direction to contract said plenum chamber, said pow-cr spring vhaving great effective strength relative to the effective pressure area of the plenum chamber end of said plunger to produce an excessive fluid pressure within said plenum chamber, a solenoid assembly positioned in relation to said plunger to operate upon energization of the solenoid assembly to magnetically force the plunger against the action of said power spring a substantial distance in a direction to contract said pumping chamber, means for controlling energization of said solenoid assembly in response to movement of said plunger in opposite directions, means defining a discharge chamber adjacent said plenum chamber, a control valve connecting said plenum chamber with said discharge chamber, said discharge chamber defining means including a movable element exposed to fluid pressure within the discharge chamber, resilient means coacting with said movable element to urge the latter in a direction for contracting said discharge chamber, said resilient means having an effective strength such that the fluid pressure within said discharge chamber' required to move said movable element through a predetermined positional range closely approaches a predetermined carburetor pressure, and means interconnecting said control valve with said movable element to effect opening and closing of said valve as an incident to reverse movements of said element through said predetermined range thereof.

4. For maintaining a continuously adequate supply of fuel to a high powered internal combustion engine carburetor, a compact highly efficient electric fuel pump capable of producing an even output pressure readily adjustable to different values, said pump comprising, in combination, a hollow body, an elongated plunger formed of magnetic material, means on said body supporting said plunger for reciprocation and forming an effective fluid seal tlierearound, means including one end of said plunger defining a plenum chamber within said body, means including the other cnd of said plunger defining a pumping chamber, fluid supply means including an inlet check valve connected to supply fuel to said pumping chamber, said plunger defining a bore extending therethrough between said chambers at opposite ends thereof, a check valve mounted on said plunger to automatically prevent flow of fluid through said bore toward the pumping chamber end thereof, a strong power spring coacting with said plunger to urge the latter in a direction for contracting said plenum chamber, a solenoid assembly positioned in relation to said plunger to operate upon energization the solenoid assembly to magnetically move said plunger against said spring in a direction for contracting said pumping chamber', a removable switch mounted on said body and connected to energize said `solenoid assembly, removable actuating means for said switch coacting with said plunger to close said switch as an incident to movement of the plunger by said spring to a predetermined position and to open said switch as an incident to predetermined movement of the plunger by the solenoid assembly to a second predetermined position, means on said body coacting therewith to define a discharge adjacent said plenum chamber', a control valve connecting said plenum chamber with said discharge chamber, said discharge chamber defining means including a flexible diaphragm supported at the peripheral edge thereof, a support head engaging the central portion of said diaphragm on the side thereof opposite from said discharge chamber, the outer' periphery of said support head terminating a substantial distance radially short of the supported peripheral edge of said diaphragm thus leaving an annular' portion of said diaphragm around said head free to pulsate to absorb pressure fluctuations within said discharge chamber, spring means operating on said head to urge said diaphragm in a direction to contract said discharge chamber, adjusting means coacting with said head spring means to regulate the residual force thereof thereby controlling the carburetor supplyingv fluid pressure with said discharge chamber required to move said diaphragm through a predetermined positional range, means connected between said diaphragm and said control valve to effect opening and closing of said valve as an incident to movement of the diaphragm in opposite directions through said predetermined positional range, and said plunger power spring having a strength related to the effective pressure area of the plenum chamber end of the plunger such that the maximum spring pressure exerted on fluid within said plenum chamber is greatly in excess of the discharge chamber fluid pressure required to move said diaphragm to effect closing of said control valve.

5. A compact high capacity electric fuel pump comprising, in combination, a body including a hollow shell, an elongated magnetic plunger, means supporting said plunger within said body shell for reciprocation and forming an effective fluid seal around the plunger, means including one end of said plunger defining a plenum chamber, means including the opposite end of said plunger and a fuel intake check valve defining a pumping chamber, a strong power spring interconnected with said plunger to urge the latter in a direction for contacting said plenum chamber, a solenoid assembly positioned in relation to said plunger supporting means to operate upon energization of the solenoid assembly to magnetically force the plunger against said power spring therefor in a direction for contracting said pumping chamber, switch means connected to controllably energize said solenoid assembly, switch control means coacting with said switch means and with said plunger to energize and deenergize said solenoid in response to movement of said plunger respectively toward and away from said plenum chamber, said plunger defining a cylindrical bore extending therethrough between said pumping chamber and said plenum chamber, narrow valve support means mounted on said plunger and extending diametrically across said bore therein, a pair of flexible check valve blades disposed within said plunger' bore and supported at the base of each blade by said valve support means, each blade having a maximum length perpendicular to said valve support means substantially greater than the radius of said plunger bore and extending from said valve support means toward the plenum chamber end of said bore, the marginal edge of each blade away from said valve support means having a generally semi-elliptical shape to seal against the adjacent cylindrical surface of said plunger bore in response to differential fluid pressure across said blades tending to produce fluid flow toward the pumping chamber end of said bore, said plenum chamber defining means including a control valve for releasing fluid therefrom, means including a fluid pressure responsive actuator mounted on said body to define therewith a discharge chamber adjacent said plenum chamber' and communicating directly with the discharge side of said control valve, means interconnecting said fluid pressure responsive actuator with said control valve to effect closing of the latter' automatically in response to a build-up in pressure in said discharge chamber to a predetermined carburetor' supplying pressure, said power spring for said plunger havinga predetermined strength in relation to the effective pressure area of the plenum chamber end of the plunger to produce within said plenum chamber a maximum Huid pressure greatly in excess of the iiuid pressure required in said discharge chamber to effect closing of said control valve by means of said pressure responsive actuator therefor, and means dening an outlet from said discharge chamber.

6. For maintaining a continuously adequate supply of fuel to a high powered internal combustion engine carburetor, a readily serviceable electric fuel pump comprising, in combination, a body including an elongated outer shell and a hollow barrel element having an inner end disposed within the medial portion of the shell, a nonmetallic guide tube extending from said inner end of said barrel element along the axis of said shell, a solenoid slidably encircling said tube, magnetic circuit means for said solenoid including a magnetic disc encircling said tube at the inner end of said barrel element and an annular magnetic retainer detachably secured to said'body shell and encircling the end of said tube remote from said barrel element, a magnetic plunger slidably disposed within said tube, an intake check valve assembly detach- `ably mounted on said retainer in covering relation to the adjacent end of said tube whereby a pumping chamber is defined between said intake valve assembly and the adjacent end of said plunger, a strong power spring interposed between said intake valve assembly and the adjacent end of said plunger to urge the latter away from said magnetic retainer, a hollow cylindrical strainer removably seated in encircling relation to said intake `valve assembly, said strainer being substantially coaxial to said tube and having a diameter approximately equal to that of said solenoid, a strainer bonnet covering the end of said strainer remote from said retainer, quick release means detachably holding said bonnet in sealed relation to said body shell, means for supplying fuel into surrounding relation to said strainer, a control valve removably secured in the end of said barrel element opposite said solenoid, the intermediate portion of said barrel element defining a plenum chamber, removable switch actuating means extending into the plenum chamber portion of said barrel element and forming a seal therewith, said switch actuating means coacting with said plunger for actuation by movement of the latter in opposite directions, said body shell defining a hollow boss substantially alined with said switch actuating means, a quickly removable switch seated in said boss and coacting with said actuating means `for operation thereby, separable means connecting said switch with said solenoid, a quick disconnect cap mounted in covering relation to said boss to hold said switch in seated position therein, said plunger defining a bore extending therethrough between said pumping chamber and -said plenum chamber, a check valve mounted on said plunger to prevent reverse flow of fluid through said bore `toward said pumping chamber end thereof, movable pressure responsive means attached rto the end of said body opposite said strainer end thereof to define with the body a discharge chamber communicating with the outlet of said control valve, means for closing said control valve in -response to movement of said pressure responsive means by ypredetermined carburetor supplying fluid pressure -within said discharge chamber, said plunger power spring having an effective strength related to the pressure area of the plenum chamber end of said plunger to produce fluid pressure within said plenum chamber greatly in excess of the fluid pressure required in said discharge chamber for actuating said pressure responsive means to close 'said control valve, and means forming a fluid outlet from said discharge chamber.

47. ln an electric fuel pump, the combination of an elongated magnetic plunger, means supporting said plunger for reciprocation and forming an effective fluid seal'therearound, means defining a plenum chamber at one end o'f said plunger, means including a fuel intake valve defining a pumping chamber at the other end of said plunger, said plunger defining a bore extending longitudinally therethrough between said pumping chamber and said plenum chamber, narrow check Valve support means mounted on said plunger and extending diametrically across said bore therein a substantial distance from the plenum chamber end of the bore, two exible valve blades each having a base thereof anchored to said valve support means, said blades being formed of a plastic material highly resistant to petroleum fuels, each of said blades extending from said support means therefor toward the plenum chamber end of said bore and having a peripheral edge shaped to separably seal against the adjacent surface of the bore, a strong power spring coacting with said plunger to urge the latter in a direction to expand said pumping chamber, solenoid means positioned in relation to said plunger to magnetically move the latter against the force of said spring in a direction for contracting said pumping chamber, and control means connected with said solenoid means and coacting with said plunger to control said solenoid means in response to reverse movements of said plunger.

8. For maintaining to a high powered internal combustion engine carburetor an adequate supply of fuel at au even adjustable pressure, a compact high capacity electric fuel pump comprising, in combination, a magnetic plunger, means supporting said plunger for reciprocation and defining an effective fuel seal therearound, means including a fuel intake valve defining a pumping chamber at one end of said plunger, said plunger defining a bore extending therethrough from said pumping chamber, a check valve mounted on said plunger to prevent reverse flow of fluid through said bore toward said pumping chamber end thereof, a strong power spring coacting with said plunger to urge the latter in a direction to expand said pumping chamber, solenoid means positioned in relation to said plunger to magnetically urge the latter against said spring therefor in a direction for contracting said pumping chamber, switch means coacting with said plunger and connected with said solenoid to control energization of the latter in response to reverse movements of the plunger, means including a control valve assembly defining a plenum chamber at the end of said plunger opposite said pumping chamber, said control valve assembly including a valve seat, a movable valve member disposed in opposing relation to said seat, a cylindrical guide skirt on said movable valve member, a guide stem extending into said skirt to guide and hydraulically check movement of the valve member toward and away from said valve seat, means including a flexible diaphragm defining a discharge chamber communicating with the downstream side of said control valve assembly. stationary means supporting the marginal edge of said diaphragm, a movable support head engaging the central portion of said diaphragm on the side thereof opposite said discharge chamber, the peripheral edge of said support head terminating lradially short of the supported marginal edge of said diaphragm to leave an annular portion of said diaphragm unsupported to pulsate to absorb incipient pressure iiuctuations within said discharge chamber, pressure control spring means coacting with said support head to urge the latter in a direction for contracting said discharge chamber, adjustable means positioned to regulate the residual stress in said pressure control spring means, means positioned to transmit reverse movements of the head supported portion of said diaphragm to said movable control valve member to effect movement of the latter toward and away from the coacting valve seat in response to reverse movements of the head supported .portion of the diaphragm, and means defining a iiuid outlet from said discharge chamber.

9. For providing to a high powered internal combustion engine carburetor a clean continuously adequate supply of fuel under proper pressure, a compact highly efficient-electric fuel pump comprising, in combination, an elongated body shell, an elongated magnetic plunger, means supporting said plunger for reciprocation within said shell and forming an effective fiuid seal around the plunger, means including a detachable intake valve assembly defining a pumping chamber at one end of said plunger, said intake valve assembly including a fuel inlet bore therein, a permanently magnetized wire shaped to clamp on said valve assembly and having opposite ends shaped to extend across said intake valve bore and magnetized to collect magnetic particles from fuel flowing through the bore, a strong power spring interposed between said intake valve assembly and said plunger to urge the latter in a direction to expand said pumping chamber, a solenoid assembly detachably mounted within said shell in position to urge said plunger against said spring in a direction for contracting said pumping chamber, a hollow cylindrical filter removably seated in surrounding relation to said intake valve assembly, a covering bonnet for said filter, quick disconnect means supporting said bonnet on said shell in housing relation to said filter, means defining a fuel inlet communicating with the outer surface of said filter, said plunger defining a bore extending therethrough from said pumping chamber, a check valve supported on said plunger to prevent reverse fiow of fluid through said plunger bore toward the intake valve assembly end thereof, means defining a plenum chamber at the end of said plunger opposite said pumping chamber, and solenoid control means connected with said solenoid assembly and coacting with said plunger to control energization of the solenoid assembly in response to movement of the plunger in opposite directions.

l0. For supplying the large and sharply varying fuel requirements of a high powered internal combustion engine carburetor, a self-contained fuel pump having an output pressure highly stabilized continuously at a limited pressure level and comprising, in combination, means defining a pumping chamber and including as a component thereof a reciprocable pumping element movable in opposite directions to expand and contract the pumping chamber, a fuel inlet check valve communicating at the downstream side thereof with said pumping chamber, means including a component portion of said pumping chamber means and defining a plenum chamber immediately adjacent said pumping chamber, a check valve mounted between said pumping and plenum chambers on said component portion of said pumping chamber means and having an upstream side communicating directly with said pumping chamber and a downstream side communicating directly with said plenum chamber, means including a component portion of said plenum chamber means and defining a fuel discharge chamber immediately adjacent said plenum chamber, a control valve mounted between said plenum and discharge chambers on said component portion of said plenum chamber means and having an upstream end communicating directly with said plenum chamber and a downstream end communicating directly with said discharge chamber, said discharge chamber defining means including as a component thereof a movable chamber expanding and contracting element spring biased with a yieldable force which moves the expanding and contracting element in a discharge chamber contracting direction against internal discharge chamber pressures less than a predetermined limited value and which allows discharge chamber pressures greater than said predetermined valve to move the expanding and contracting element in a discharge chamber expanding direction, means coacting with said expanding and contracting element and with said control valve to effect opening and closing of the latter by movement of said expanding and contracting element in chamber contracting and expanding directions respectively, a damper connected to said control valve to steady opening and closing movements thereof,

reciprocating means coacting with said reciprocable pumping element and including a powerful spring connected with said pumping element to urge the latter in one direction and including externally energized power means coacting with the pumping element to intermittently move the latter in the opposite direction against said spring, and said reciprocating means having sufiicient strength to pump into the plenum chamber a maximum pressure greatly in excess of said predetermined limited value and being yieldable against a plenum chamber pressure in excess of said maximum pressure.

ll. ln a fuel pump of the type in which a piston is reciprocated in a cylinder by an electro-magnet and by a return spring engaging the piston to pump fuel from a pumping chamber to a second chamber to which an outlet is connected and in which inlet and check valves are provided for preventing reverse flow of fuel through the pump, wherein the pump is characterized by: the piston return spring being oversized; a third chamber integral with the pump, disposed immediately adjacent the second chamber, and interposed between the second chamber and the outlet; a relatively unrestricted passageway interconnecting the second chamber with the third chamber to provide substantially no line pressure drop between the chambers; a third valve disposed in the passageway; ing element in first and second opposite directions to and an elastic element in the third chamber operatively connected to the third valve for reducing and regulating the pressure of the fuel flowing from the second chamber into the third chamber, thereby to provide a high capacity, 'fast response pump characteristic.

12. For supplying fuel to an internal combustion engine, a high capacity constant pressure fuel pump comprising a reciprocable pumping element; means including one surface of said pumping element defining a pumping chamber; a first and second power means for urging said pumping element in first and second opposite directions to respectively draw fuel into said pumping chamber under vacuum and to force fuel from said pumping chamber under pressure; one of said power means operated by an external source of power, the other comprising an oversized power spring in operative engagement with the pumping element and capable of producing a force substantially in excess of that required for desired fuel pump discharge pressures; the power means causing discharge of fuel from the pumping chamber being elastic and capable of producing a fuel discharge pressure substantially greater than desired fuel pump output pressures; inlet and outlet check valve means for said pumping chamber; means integral with the pump immediately adjacent said pumping chamber and directly connected therewith defining a plenum chamber; said outlet check valve interposed between said plenum chamber and said pumping chamber; means integral with the pump immediately adjacent said plenum chamber and directly connected therewith defining a fuel discharge chamber including a yieldable element preconditioned to move reversibly in response to changing fluid pressure within the discharge chamber; a control valve'interposed between said plenum chamber and said discharge chamber; and linkage connecting the control valve and the yieldable element for urging the control valve toward closed position incident to movement of the yieldable element by an increasing pressure within said discharge chamber to a predetermined value and urging the control valve toward open position incident to movement of said yieldable element by a slight decrease in the discharge chamber pressure below said predetermined value.

13. A fuel pump for supplying the large and sharply varying fuel requirements of a high pressure internal combustion engine carburetor comprising; a pumping chamber; a plenum chamber communicating with one side of the pumping chamber; a fuel inlet communicating with the other side of the pumping chamber; a reciprocable element in the pumping chamber and inlet and outlet 18 the plenum chamber to permit substantially no line pressure drop between the chambers; a third valve disposed in the passageway; and an elastic element in the third chamber connected to the third valve for reducing and regulating the pressure of the fuel flowing from the plenum chamber into the third chamber.

References Cited in the file of this patent UNITED STATES PATENTS Whitted May 9, 1933 Miller Feb. 8, 1949 UNITED STATES PATENT OFFICE CERTIFICATE 0F CORRECTION Patent No 2, 872, 871

.Arthur Cu, Allen It is herebjr certified that error appears in theprinted specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 5, line 65, for n(hot shown)H read m- (not, shown) column lo,

linel 26, strike out "ing element in first and second opposite directions to'h1 Signed .and sealed this llth day of August 1959 (SEAL) Attest:

KARL ,Ht

ROBERT C. WATSON Attesting Oficer Commissioner of Patents February lO 1959

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