US2953100A - Percolator pump construction - Google Patents

Description

Sept 20, 1960 T. E. ANDREWS 2,953,100

PERCOLATOR PUMP CONSTRUCTION Filed Aug. 2, 1957 2 sheets-sheet 1 ig x7@ @i 'Zg .24 72 f/Wm/aff Hwa/aref.' Ao/ws Sept. 20, 1960 T. E. ANDREWS 2,953,100

PERcoLAToR PUMP CONSTRUCTION Filed Aug. 2, 1957 2 Sheets-Sheet 2 Maar/are [Abd/@ws @y M f /7/3 //amgy United States Patent Or PERcoLAroR PUMP CONSTRUCTION Theodore E. Andrews, Orefield, Pa., assigner to General Electric Company, a corporation of New York Filed Aug. 2, 1957, Ser. No. 675,959y

6 Claims. (Cl. 10S-231.5)

The instant invention relates generally to percolators and particularly to an improvement in the means for pumping liquid in percolators during their operation.

As is well known, percolators are widely used in American homes to brew coffee, particularly during the early morning at breakfast time. When so used, it is extremely desirable that the percolator brew coiee in the quickest and quietest manner. The time required to brew coffee is largely dependent upon the efficiency, i.e., the pumping rate, of the means in the percolator for pumping liquid during operation thereof. The yamount of noise made by a percolator is also largely dependent upon the construction of the means in the percolator for pumping the liquid during operation thereof. Most people have been vexed in the diflicult hectic morning hours by having to wait for coffee to brew and/or by being disturbed by having to listen toa noisy percolator brewing coffee. The percolator art has recognized the seriousness of the problems of: (l) lack of speed, and (2) presence of noise in existing percolators, and as a result much effort has been directed toward eliminating them. Notwithstanding this effort, it is not believed that a sufcently quick and quiet percolator has been heretofore developed.

It is an object of this invention to provide an improved percolator that includes improved liquid pumping means which is both eflicient and quiet in operation.

It is another object of this invention to provide an improved liquid pumping construction for a percolator which affords practical operational conveniences in assembling the parts for use, in removing some of the pumping parts and temporarily resting them outside of the percolator, Iand in ease of cleanability.

The objects of Ithis invention are achieved in one form by the provision in a percolator having a pump well of a pump assembly which includes an elongated pump tube which has an apertured pump body fixed to it near its lower end, a washer which is movably mounted on the pump tube adjacent to the pump body and is adapted during operation to periodically close the apertures in the pump body in a manner which is known to the percolator art, and a cup-shaped pump baffle which is rigidly secured to the pump tube adjacent the washer. The configuration, dimensional relationship and disposition of the pump assembly parts are such as to effect a temporary pump construction when the pump Aassembly is operatively associated with the pump well which differs from known percolator pump constructions principally in that it includes the referred-to, cup-shaped pump baiile, which has portions which extend downwardly beyond the lower end of the pump tube and which are generally uniformly spaced from the pump tube and the side walls of the l pump well.

The above `and other objects and further details of that which I believe to be novel and my invention will be clear from the following description and claims taken with the accompanying drawings wherein:

2,953,100 Patented Sept. 20, 1960 Fig. l is an elevation View, with portions broken away and shown in section for the sake of clarity, of a percolator which incorporates the improved pump construction;

Fig. 2 is a'vertical sectional view of the pump construction shown 4in Fig. l on an enlarged scale;

Fig. 3 is a sectional view taken substantially on line 3 3 of Fig. 2;

Fig. 4 is a fragmentary perspective view of the pump assembly, particularly showing the lower end thereof;

Fig. 5 is a schematic view of a currently widely used, prior art pump construction showing the operation thereof; and

Fig. 6 is a schematic View similar to Fig. 5 showing the improved pump construction.

By reference to the drawings, and particularly Fig. l, it will be seen that the improved pump construction may be incorporated in a percolator, such as the one indicated generally by reference character P, which includes the body 10, the spout 12, the handle 14, the base 16, and the lid 1S. Within the percolator there is formed a liquid reservoir 2i) which is defined by a major portion of the percolator body, the lid and an interior, horizontal, bottom wall 22. It will be understood that notwithstanding the fact that the illustrated percolator is one of the automatic electric type, this being the preferred type, that the improved pump construction can be utilized in any percolator and does not necessarily have to be used in an electric or automatic one.

The illustrated percolator includes a pump well 24 which depends below the bottom wall 22. The pump well is formed by pump well cup 26 which comprises circular well bottom wall 28, cylindrical well side walls 30 and an annular mounting flange 32. It will be observed, particularly in Fig. 2, that the pump well cup 26 may be inserted from above through the opening 34 in the percolator bottom wall 22 and have its flange 32 supported on the portions of the percolator bottom wall 22 which surround the opening 34 with an annular sealing gasket '36 compressed therebetween. It will also best be seen in Fig. 2 that the lower exterior surface portions of the well side walls 30 are threaded and co-operate with internal threaded portions of the pump heater member 38 to mount the latter on the lower side of the percolator bottom wall 22 with the sealing gasket 40 compressed between the pump heater member and the lower side of the percolator bottom wall.

The pump heater member 38 includes the heater 42, which may be of the widely used sheathed electrical resistance heater type, which is embedded in said member. The construction of the percolator and pump well described thus far is well known, as is the practice of utilizing with such construction a pump assembly comprising a vertically extending pump tube, such as illustrated pump tube 44, which supports a removable coffee basket, such as the illustrated coffee basket 46 near its upper end, and a rigidly mounted, apertured, dished, disc-like pump body and associated movable pump washer, such as the illustrated parts 48 and 50, respectively, near its lower end. The manner in which the pump Well construction and a pump assembly of the type set forth thus far co-operate to produce pumping operation in a percolator is well known. This general type of percolator pump construction iS widely used in practice and is generally disclosed in many prior art patents, for example, in U.S. Patent No. 1,922,- 546 (fFig. 3). It has been found in practice that percolators including this type of known pumping construction: (l) operate in a noisy manner which is characterized by periodic loud thumping noise, and (2) do not have an entirely satisfactory pumping rate. It has been found in practice that the addition of another particular structural element to the known pump assembly c011- struction in a particular manner substantially eliminates the objectionable thumping noise inherent in the known constructions and increases the pumping rate appreciably, thereby reducing the amount of Itime required to brew coffee. This particular element has been designated as a pump baille and, as illustrated, takes the form of an inverted, cup-shaped member 52, which is rigidly secured to the pump tube 44 near the latters lower end.

It will be observed in Fig. 2 that the referred-to pump body 48 includes the dished-portion 54 and the central llat portion 56 which has a plurality of spaced openings 58 formed therein. It will also be observed Lin Fig. 2 that the pump body 48 is rigidly connected to the pump tube 44 between and by the annular bead 60 formed on the pump tube and the hub 63 of collar 62, which in turn is rigidly mounted on the pump tube. It will also be observed that the pump washer 50 is mounted on the exterior of the hub 6.3 of the collar 62 so as to be freely slidable thereon between the limits fixed by the flange 64 of said collar and the circular bosses 66 formed on the lower side of ilat portion 56 and which surround the openings 58. Lastly, it will be observed that the pump assembly is adapted to be temporarily removably positioned in the percolator body in such a mannerthat circumferential portions of the outer surface of the dished portion 54 of the pump body 43 rest on the circular valve seat 68 formed in the general Vicinity of the intersection of the cylindrical well side walls 30 and the flange 32 of the cup-shaped pump member 26. When mounted in this manner, the pump well 24 becomes a pumping chamber which is `adapted to periodically communicate with the reservoir 20 through the openings 58 during operation of the percolator, all in a known manner.

Rigidly secured to the pump tube 44 near the latters lower end is the previously mentioned pump baille 52. The pump baille performs vital, novel functions and includes the llat annular portion 7l), the cylindrical peripheral skirt 72 and the central cylindrical mounting flange 74. The pump baille is secured tightly on the pump tube -44 near the latters lower end by a press fit caused by the outwardly flared tube end 76, which in actual practice may serve as a convenient means for securing all of the parts carried by the lower end of the pump tube.

When the improved pump assembly is mounted in the percolator body, the parts are disposed as illustrated in Fig. 2. In these positions, it should be noted that the following conditions obtain: The pump ibody 48 rests on the valve seat 68 and co-operates with the pump well steam pressure causes water in tube 44 to be forced up through the open end thereof, whereupon the open upper end of the tube is exposed to atmospheric pressure thus equalizing the pressure in reservoir and pump well 24. When this occurs pump washer 50 returns to its lowermost position, and the cycle Iis repeated. The foregoing conditions obtained in the prior art pump construction alluded to previously. The following conditions relating to the pump baille are novel and significant: The cup-shaped pump baille 52 is disposed within the pump chamber formed by the pump well 24 in such a manner that its skirt y72 is disposed substantially co-axially with the cylindrical purnprside walls 30 and the pump tube member 26 to transform the pump well 24 into a substantially closed pump chamber. The pump washer is freely slidable on the hub 63 of collar 62 for Vertical movement between the collar flange 64 and the bosses 66. When the pump washer 50 is in its lowermost position, illustrated `in Fig. 2, the interior of the percolator reservoir 20 communicates with the interior of the pump chamber formed by the pump well 24 through the openings 58. It will be understood that if liquid is in the percolator reservoir 26 and the pump construction is in the Fig. 2 condition, that liquid will flow through the openings 58 into the pump well and till the latter. It will also be observed that when the pump washer 50 is moved to its uppermost position (not shown) duringoperation of the percolator by the pressure of steam generalted within pump well 24 each time a charge of water enters the well and is heated by heating element 42, the washer 50 contacts the bosses 66 and temporarily discontinues communication between the percolator reservoir 20 and the pump Well 24. It will be understood that the outer diameter of pump washer 5G and the inner diameter of pump well 24 are so proportioned that as steam is generated in the well the pressure on ithe underside of washer 5t) exceeds the pressure on the upper side thereof, and that it is this pressure differential which causes washer 50 to move to its uppermost position. lFurther, this 44, is spaced uniformly within said cylindrical pump side walls, and is spaced about said pump tube. Also, the lower edge of the skirt 72 of the pump baille extends downwardly beyond the lower end 76 of the pump tube In order to fully appreciate the significant differences in structure and operation of the prior art construction and the improved construction contemplated by the instant invention, it is believed desirable to iirst review the manner-in which the prior art pump construction operates. This operation -is illustrated schematically in Fig. 5, wherein it will be observed that during operation of the percolator, a charge of 4water ilows down through the openings in the pump body PB from the percolator 4reservoir into the pump well chamber PW when the pump washer WP is in its lowermost position, yand that on being heated by the heater PH, the water in the pump well chamber is agitated and bubbles of steam are formed which cause an increase of pressure in the pump well chamber forcing the water up the pump tube PT. When this occurs, the pump washer WP moves upwardly and temporarily Vcloses the openings in the pump body PB. As the heated water moves upwardly through `the pump tube PT, pressure within the pumping well chamber PW will diminish t-o the point wherein it is -less than that within the reservoir. At this time, the pump washer WP moves downwardly and allows cold water to enter through the pump body openings into the pump well chamber PW. The condition which lexists at this time during operation of the prior art pump construction is illustrated in Fig. 5, wherein it will be observed 'that the newly admitted cold water, indicated by the schematic -arrows which are pointing downwardly, meets with the heated water and steam which remains in the pump well chamber from the previous charge and which is being moved upwardly, and a considerable amount of turbulence results. It is the sudden clash of newly admitted cold water with the remaining heated water and steam which is believed to cause both a temporary slow-ing down of the pumping rate and the thumping noise which is characterized by the prior art pump construction.

The operation of the improved pump construction is illustrated in Fig. 6, which illustrates` the condition during the point in operation which correspond to the point of operation of the prior art construction illustrated in Fig. 5. In other words, Fig. 6 illustrates the condition of the improved pump construction at the time of operation during the terminal portion of pumping upwardly a'charge of water when the pressure within the pump well chamber 'formed by pump well 24 has diminished and coldwater is admitted from the reservoir through the openings 58 in the pump body 48. The downwardly llowing cold water is indicated by the downwardly directed schematic arrows, and the upwardly flowing heatedwater and steam which remains from the previous ,charge is indicated by the upwardly directed Vschematic arrows and bubbles. It will be seen in Fig. 6 that relatively no turbulence results from the mixing of the newly admitted cold water for the next charge of water to be heated and pumped, and the In fact, because of the operation of the improved pump construction, and principally due to the benets which flow from the incorporation of the cup-shaped pump bafiie 52, the `operation is so smooth that there are not any distinct charges of cold Awater that are heated and then pumped off. This obtains, because the incoming cold water which flows through the openings 58 is directed outwardly by the pump washer 50 and downwardly between skirt 72 of the pumpbaie 52 and the cylindrical well -side walls 30 of the pump well member 26. During its downward flow, the newly admitted cold water is warmed up, and by the time it reaches the lower part of the pump well v24, that is, the part below lthe lower edge of the skirt 72 of thepump baffle 52, it has been substantially heated; therefore, there is no sudden contact or clash between `cold water and heated water and steam as is the case in the prior art pump construction. When in the lower part of the pump well, the newly admitted, ywarmed water mixes with the heated water remaining from the previous charge of water, is heated `further and pumped 01T; this overall operation, in effect, provides for a smooth transition of the newly admitted water from its cold state to its heated state when it is pumped up through the tube 44. This provides the dual benefits of `smoothing out the pumping operation and thereby increasing the pumping rate and efficiency of the pump construction, and of eliminating the objectionable thumping noise which periodically is made by the prior art pump construction.

It has been found in practice that in order to achieve most successful results, certain particular dimensional relationships between some of the parts of the pump construction must be maintained. Two such dimensional relationships are indicated in Fig. 6; the dimension indicated as X, IWhich represents the vertical distance between a plane passing through the lower edge of the pump tube 44 and a plane passing through the' lower edge of the pump baflie skirt 72, must `fall within the range of .030 in. to .050 in., andthe dimension ind-icatetd by Y, Iwhich represents the radial distance between the outer `surface o-f the skirt 72 and the inner surface of the cylindrical well side walls 30, must fall within the range of .070 in. to .090 in. ln practice, the two specific dimensional relationships `Set forth were found to be necessary in order to 1fully achieve Ithe objects of this invention, when they were incorporated in a pump construction having the following dimensional relationship: the pump well had a diameter of 1.0() in. and a depth of .625 in.; there were eight openings in the pump body which were circumferentially spaced on a circle having :a diameter of .562 in.; and the pump washer had a diameter of .828 in., a thickness of .047 in., and was movable an axial distance of .015 in.

Although the principal objects of eliminating objectionable noises inherent in prior art pump constructions and increasing the pump rate thereof are fully accomplished by the improved pump construction disclosed, it is believed important that several subsidiary advantages of the improved pump construction also be recognized: (l) One fault of the prior art construction illustrated schematically in Fig. 5 is that it is difiicult to properly locate the removable pump assembly with relation to the pump well when initially assemblying the percolator for use. It is, of course, necessary that a good tight seal be effected between the pump body and the seat formed by the pump member. The presence of the cup-shaped pump baie in the improved pump construction provides 'an effective means for positively locating the pump assembly with regard to the pump well, and substantially eliminates the possibility of misalignment of these parts; (2) 'Ihe addition of the pump baffle does not in any way detract from easy cleanability of all surfaces of the pump assembly. It will be understood that this is important in a coffee percolator wherein it is undesirable to permit coffee grounds to become embedded in functioning parts,

and ('3) t will be observed in Fig. 5 that when removing the pump assembly of the prior art construction, let us say, after coffee has been brewed and itis desired to reheat the coffee without the pump assembly and coffee basket being present in the percolator receptacle, that there is no convenient way of removing these parts and placing them on a kitchen surface. This problem does not exist when using the improved construction, because the lower edge of the cup-shaped pump bafile provides a handy means for resting the pump assembly with the coffee basket mounted thereon on a kitchen surface when it is desired to remove it from the percolator.

As will be evident from the foregoing description, certain yaspects yof my invention are not limited tothe par-ticular details of construction of the example illustrated, and I contemplate that various other modifications and applications will occur to those skilled in the art. It is, therefore, my intention that the appended claims shall cover such modifications and applications as do not depart from the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Paten-t of Ithe United States is:

l. In a percolator comprising: a liquid reservoir; a pump well including side walls below said reservoir; said pump well having an opening placing said reservoir and said pump Well in communication with each other; means thermally associated with said pump well for supplying heat to the side walls thereof; an elongated pump tube adapted to be removably mounted in said reservoir; a pump body rigidly secured to said pump tube near an end thereof and adapted to temporarily substantially close said opening when said pump tube and said pump body are mounted in said reservoir for operation and thereby temporarily disrupt communication between said reservoir and said pump well; said pump body including means for placing said reservoir in limited communication with said pump well; and movable valve means supported on said pump tube adjacent to said pump body for periodically rendering said pump body means inoperative to place said reservoir and said pump well in communication; whereby during `operation of said percolator, small amounts of cold liquid from said reservoir periodically flow through said pump body into said pump well where they are heated by said heating means and pumped up through said pump tube, that improvement comprising a pump baffle rigidly secured to said pump tube near said pump tube end and located below said valve means when said pump tube is mounted in said reservoir; said pump *baille having a skirt portion which encompasses said pump tube end and which extends below said pump tube end when said pump tube is mounted in said reservoir; and said pump baie being encompassed f by said pump well so as to cause said small amounts of cold liquid to flow downwardly between said bafle skirt and the heated side walls of said pump Well or a substantial distance before owing inwardly toward said pump tube end, whereby shortly after operation of the percolator commences the cold liquid is warmed after it enters said pump well but before it contacts the heated liquid remaining centrally in said pump well from the previous amount that has been heated and pumped off and thereby mixes with it without creating any appreciable amount of turbulence, thereby minimizing noise and any tendency to retard the pumping rate.

2. A device as defined to claim l wherein said pump baiiie comprises an inverted cup-shaped member and includes a peripheral wall surface that is spaced from said pump tube and the walls which form said pump well, and extends downwardly below said pump tube end when said pump tube is mounted in said reservoir.

3. A device as defined in claim 2 wherein said well and said pump bafe `are both generally cylindrical and a predetermined dimensional relationship exists between some of the parts which is proportional to the following: the pump well diameter is 1.00 in., the pump well depth 7 is .625 in., the radial distance between said peripheral wall surface and said pump well forming walls falls in the range of .O70 to .090` in., and saidperipheral wall exltends below -said pump tube end a distance falling in the range of .0,30 to .050 in.

4. A device as defined in claim 1 wherein said pum well has cylindrical side walls and said baffle comprises an inverted cup-shaped member having a iiat wall that extends lradially away from said pump tube toward said cylindrical side walls and a downwardly extending cylindrical wall which is uniformly spaced within said cylindrical side walls and extends downwardly below said pump tube end when said pump tube is mounted in said reservoir.

5. A peroolator compnising: walls forming a liquid reservoir and a cylindrical pump well which is disposed below said reservoir and communicates therewith; means connected to said pump well for heating the walls thereof; a circular seat formed by the intersection of Isaid pump well and said reservoir; a removable pump assembly adapted to be temporarily mounted in said reservoir during loperation of said percolator; said pump assembly comprising an elongated pump tube; a disc-like pump body having apertures therein rigid-ly secured to said pump tube near one end thereof; a pump valve washer slid-ably mounted adjacent to said pump body and arranged to periodically close the apertures tin said pump body during operation; and a cup-shaped pump baffle rigidly secured to said pump tube between said one tube end and said pump valve washer; said pump baie'having a cylindrical skirt that extends beyond `said yone tube end; whereby when the pump assembly is mounted in said reservoirin operative position, said pump body seats on saidl circular seat, said pump valve washer, said pump bathe and a portion of said tube including said one tube end are disposed within said pump well, the remainderof said pump tube extends upwardly above said pump well into said reservoir, and said pump baffle skirt is co-axial with4 and spaced within the heated walls of said pump well, and extends downwardly beyond said one tube end.

f6. YA device as dened in claim 5 wherein a predetermined dimensional relationship exists between some of the parts which is proportional to the following: the pump well diameter is 1.00 in., the pump well depth is .625 in., the radial distance between said skirt and the inner side surface of said pump well falls in the range of .070 to .O90 in., and said skirt extends below said one tube end a distance falling in the range of .030 to .050 in.

References Cited in the le of this patent UNITED STATES PATENTS 1,743,342 Halstead et al. Jan. 14, 1930 1,922,546 Lucia Aug. l5, 1933 2,784,678 Graham Mar. l2, 1957

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