US2603158A - Lubricating pump - Google Patents

Description

July 15, 1952 G. NEMETZ LUBRICATING PUMP 2 SHEETSSHEET 1 Filed July 28. 1947 Fig? A INVENTOR. Guafiavflmeiz, mceweab,

15, 1952 NEMETZ 2,6@3,l5

LUBRICATING PUMP Filed July 28. 1.947 2 SHEETSSHEET 2 rmm a ml IN V EN TOR.

Patented July 15, 1952 HTED s LRICATING PUMP Gustav Nemetz, deceased, late of Vienna, Austria,

by Valerie Nemetz, administratrix, Vienna,'Austria, assignor to Alex. Friedmann, Kommandit- Gesellschaft, Vienna, Austria Application July 28, 1947, Serial No. 764,144 In Germany November 4, 1943 Section 1, Public Law 690, August 8, 1946 Patent expires November 4, 1963 Way of a drop nozzle, and a delivery piston forcing the oil distributed to the lubricating point, and consists essentially in that the working cylinder of the distributing piston is formed in a member which moves when the pump is operated, while the operation of the distributing piston is derived at least in part from the movement of the member containing the distributing piston. Such a design produces an advantageous construction, and in simple manner permits the designing of a moving member necessary for the operation of the pump and serving at the same time to operate the distributing piston, or on the other hand the utilization of the member forming the cylinder of the distributing piston for some other additional function. Thus, according to the invention, this member is preferably designed as supply piston, which supplies the lubricant under pressure to the Working chamber of the distributing piston, and thus, even in the case of a lubricant which is viscous or of thick consistency, ensures perfect filling of the working chamber of the distributing pump.

According to the invention, the arrangement is such that the suction stroke of the distributing piston is forcibly brought about or supported by the pressure of the oil supplied to its working chamber by the supply piston, so that under any conditions the suction stroke of the distributing piston is ensured. The distributing piston can be compelled to perform the delivery stroke by a stop which is adjustable for the purpose of varying the amount distributed but immovable during the working cycle of the pump, and against which it is brought by the movement of the supply piston. The distributing piston may, however, for the purpose of forcibly bringing about its delivery stroke be connected, in such manner as to be unable to move axially, to the fixed regulating device provided for the adjustment of its stroke. The pump action of the distributing piston is then obtained by the movement of the member of the pump unit, such as the supply piston, which contains its working chamber.

In order to permit the escape of the excess oil forced into the working chamber of the distributing piston from the working chamber of the supply piston during the latters compression stroke, a lateral pressure release aperture is conveniently provided from the bore containing the distributing piston. This aperture is opened by the dis- 13 Claims. (Cl. 103-5) tributingpiston during the "suctionstrokawh'e oil under pressure flows into its working chamber, and the distributing piston slides over and closes it during its delivery stroke. During the suction stroke, therefore, the working chamber of the distributing piston is flooded with oil under pressure, and it is impossible for its working chamber'not to be completely full of oil at the commencement of the compression stroke andfor inaccuracies in.

the delivery of the pump unit to occur.

In the drawing the invention is diagram-- matically illustrated with the aid of examples. Figs. 1 and 3 show two' vertical cross-sections through lubricating pumps having pump units designed in accordance with the invention, while Fig. 2 shows details of the upper end of the distributing piston of Fig. 1 ma section at'rightangles to the sectional plane of Fig. 1.

The pump units in the example illustrated in Fig. '1 are driven by an eccentric shaft l, which carries one eccentric disc 2 for each pump unit. On each eccentric disc 2 is mounted a double lever3, the forked end 4 of which encloses arod 5 which is stationary in the pump housing, so that "that lever end is guided as the eccentric shaft l turns, whiie'its other end, which is in the form? of a spherical pin 6, describes a reciprocating movement. The spherical pin 6 thus drives the appertaining pump unit by engaging in a transverse bore 1 in a bolt 8 guided in abore 9 in the body ll] of the pump unit. The pointof application of the spherical pin 6 lies within the cross-sectionof the bolt.

The bolt 8 is thus moved to-and-fro' with a uniform stroke, and from it both the delivery piston II and the distributing piston [2 of the pump unit derive their movements. The delivery piston II, which lies in a bore [3 parallel to the bore 9 in the body In, is immovably connected by a crosshead [4 to'the end of the bolt 8 projecting-from the bore 9. The cross-head l4 encloses the end of the delivery piston I I, with agood fit,'between the shoulders of a groove [1, and with a second fork similarly encloses the end of the bolt 8 by engaging in lateral recesses therein between the surfaces l5 and 16 (see also Fig. 2). Every axial displacement of the bolt 8 is therefore accompanied by the same axial displacement of the delivery piston l I.

In addition a blind bore i9, into which the distributing piston l2 is'fitted, is bored into the face of the boltend 8 which carries the cross-head I l. The distributing piston has, in an axial bore. 22, a

spring-loaded overflow valve 20, which releases.

when a corresponding pressure occurs in the bolt as far as a groove-like cavity 58 in the sur- 1 face of the bolt. In the hollow surface of the cylindrical bore 9 is provided an axially parallel cavity 59 extending from :its lower'endupwards to a certain height. The cavities 58 and '59 "form a control, the purpose below.

In addition, the pressure passag'e 29 leadsfrom the working chamber 2! of the distributing piston I2 radially out of the bolt 8, and discharges to the surface of the bolt into a cavity E'Ipwhich connects with the opening of the part 29 of the pressure passage, which continues in thebody H] of the pump unit, in the illustrated highest posi non-or the bolti8. .Aco'nt-rolfor thepressurepas= rsage z29, .29 is thereby Jformed. The'bore 129' :crosses the cylinder bore 13411 which lies the delivery piston II. The latter has a groove at, which connects the vpartsof the-portion29 of the pressure passage which "are interrupted by *the'bore [3. The groove '30fis'of'such a'width' that it controls the passage through the pres sure passage '29 j' in the "same manner as is done of which 'will'be explained by the movements ofthebolt cavity '51 relatively to the aperture of the portion 29' of the pressure passage. The groove 30 thus has the smallest possible width. This alignment of the passages, in'conjunction'with the groove 39, is advantageous for reasons of manufacture, since in this way theaxes .ofb'oth" the "bores Sand l3 and the pressure "passage 29,229, andthat of the drop nozzle i'canl1iein one-plane.

The body to o-fithe pump unit is fastened to the cover .3liiby means of .the screws Mandthe *outlet'nipple .33. A plurality of pump units can beimounte'd side by Side on the same "cover :31 'A'ibowl iifi', to which is connected a bowl portion "36' in the body Illof 'ea'ch pump unit; is :pro-

vided in the coverv 3|:to collect the drops falling from the 'nozzle '35. The bowl parts are separatedifrom'one another'by a part '38, designed after the style of Ta sieve, of a packing plate 38 disposedbetween the bodies l'll'ofthe'pump units and the cover (H. The insertion.aperature 54 in the pump housing 31'is'clos'ed by means-of tiie cover'3l.

From the bowl 36' a suction passage '36" leads to -the working chamber 34 of the delivery piston H,- and is'b'ounded atthe bottom by a control piston '3 9' which is guided'in the' cylinder bore l3 and 'actsafter the manner of'a'valve. The control piston iiil is pressed upwards by the spring '40, so that it constantly seeks to'slide over and close the delivery passage '42 leading out of the bore 13. This passage is continued by'th'e connecting nipple '33 in the direction of the lubricating point. 'Thehighestposition of' the control piston 39 is determined 'by a collar 4|. A projection 43 on "the lower end of the bolt 8' engages beneath this "collar in such a manner that, as the bolt 8 moves upwards, the control piston '39 is carried with it in the event'of the failure of thespri'n 'liband closes the pressure passage 42. The bottom end ofthe bolt; 8 "andthe spring-loaded endof the control piston 39 both'lie in the hollow space 44 of 'a 'cap'46, which is tightly fastened to the body It ofthe'pump uni-t by'means of'screwsf lfi, and

- which forms the working chamber for the b01138 acting as supply piston.

4. The pump unit Works as follows: When the shaft l is driven in any rotational direction, the bolt 8 is moved up anddown with uniform stroke by the "sphericalpin '6 of the lever 3, and by means of the cross-head 14 carries with it the delivery piston II, which in the position illustrated, is just beginning its delivery stroke from top to bottom. The bolt 8 penetrates with its lower end into the working chamber '44, and first forces the oil back through the aperture -'41 into the oil storage vessel of the pump housing 31, until its control edge 48 covers the aperture of the bore 41, whereupon the oil,

in the working chamber 44 is placed under superatmospheric pressure. In the meantime, the cavity 5'! on the bolt 8 has moved so far down that passage through the pressure passage 29,

28" is interrupted, whereupon the groove-like cavity 58 connects with the cavity 53 of the bore 8, so that the chamber 44 is brought into com- -munication with the working chamber-2| o'f'the distributing piston 12 by way ofthe cavities 59, '58, the longitudinal groove-24, and the transverse passage 23. The oil under pressure then flows i out of the working chamber ,44 into the working chamber 2|, and forces the distributing piston i2 upwards out of the blind bore I 9, until its shoulder l8 bearsagainst the lower surface W of the cross-head H. The excess amount of oil iorced out of-the'working chamber into the working chamber 2| escapes through the overflow valve 29 and the outlet aperture'22 and,

lubricating the driving parts of the pump'uni-t onits wayi-flows off. r

Simultaneously with the bolt 8, the delivery piston H also moves downwards and penetrates into :its working chamber 34-, enclosing between its lower :faceand the upper face of the control piston 39 an a-mount of oil which, overcomingthe power of the-control piston spring-40 it" pushes down together with the control piston 39, until the upper facexof the control piston 39" arrives beneath the aperture of the delivery passage 42, through which the oil is forced through the nipple '35' to the lubricating point. The downward movement of the control piston. with'the c ollar 4| is limited by the shoulder 50011 the cap trol piston 39- and its guide 13 passes backinto the bowl 36 by :way of the groove 5| and'the bore 52. i 7

During their suction stroke, the bolt "8 and the delivery piston {I move upwards. A negative pressure is produced'in the working chamber 44 of the bolt 8 and, as long as said chamber remains incommunication with the working chamber 2| of the distributing piston 12, also in the latter chamber, until the control edge '48 of the bolt 8 slides upwards over thes'uction aperture 4i and opens it. Thereupon oil is sucked into the'worki'ng' chamber 44 from the storage'vessel in the pump housing 31, by way of the suction passage '41. r

In order to prevent the distributing piston 12 from being'sucke'd downwards into the blind bore '19 by the negativepressure in the working'chamber 44, a brake is provided for the distributing piston l2, which consists of a clamp spring-6i! held in'a groove in the cross head l4 (see Fig.2). Shortly after the commencc'ain'entof'the' suction stroke of thebolta, communication between'the cavities 59 and 58', and hence communication between the working chambers 44 and 2!, is interrupted. Towards the end of the-suction stroke the cavity 51, into which discharges "the Oil passing downwards between the con pressure passage 29 which'leads out of the working chamber 2I' comes into communication with the portion 29' of the pressure passage. Thereupon, the upper end of the distributing piston I2 strikes against the regulating screw 53 and, depending on the setting of the regulating screw 53, the distributing piston I 2 is forced to a greater or lesser extent into the blind bore I9, delivering an accurately measured amount of oil from the working chamber ZI, through the passage 29, the cavity 5?, the portion 29' of the pressure passage, and the groove 32 in the delivery piston I I, to the drop nozzle 35. Since this delivery takes place during the period of quite low load on the driving parts of the pump unit (at this time only the suction strokes of the bolt 8 and delivery piston I I are b eing carried out) and the working chamber 34 is not under pressure, no inaccuracies in the delivery of the distributing piston I2 on the score of elastic deformations of the pumpunits can occur.

In the position of the r gulating screw 53 illus trated in Fig. i, there is no delivery stroke for the distributing piston. In order to obtain such a stroke, the regulating screw 53 must be screwed down as required. In this manner regulation'of the delivery amount of the pump unit between zero and a certain maximum value is possible.

- From the drop nozzle 35 the oil falls into the bowl 38 of the cover 3! and, purified by the sievelike part 38' of the packing plate 38 lying between the body Ill of the pump unit and the cover 3!, flows into the bowl part 35' and thence by way of the suction passage 35" into the working chamber 34 of the delivery piston I I,

Owing to the force of the spring 40, the c0n== trol piston 38 also follows the upward suction stroke of the delivery piston II. If that force should not be suflicient for the purpose, it is pushed upwards by the projection 43 on the bolt 8, which bears from below against the collar ll. The control piston, in moving upwards, slides over and closes the delivery passage 42,

As can be seen. the pump unit is of very simple design. The fitting bores for the pistons are disposed parallel to one another in the body It of the pump unit, and can therefore be made with the required accuracy at little expense of labor. The assembly of the individual parts is also a simple task, mistakes being impossible.

In Fig. 3 is illustrated a similar lubricating oil pump unit designed in accordance with the in vention. Communication between the working chamber 44 of the bolt 8 working as supply piston and the working chamber 2! of the distributing piston I2 is in this case established by a bore 26 in the bolt 8, which contains a check valve 21 opening upwards, the seat of which is formed by a screw cap 28. A bore 25 leads radially from the bore 26 to the lateral longitudinal groove 24 in the surface of the bolt, so that controlled communication is established between the working chambers 44 and 2I by way of the passages 23, 24, 25, and 26 and the check valve 21. p

The distributing piston I2 is joined in this embodiment to the regulating screw 53 by a claw connection which prevents axial displacement, so that it is held fast relatively to the bolt 8 in every position of the regulating screw 53, and performs in the blind bore I9 the same stroke as the bolt 8 in the bore 9 of the body ID of the pump unit.

As an overflow for the excess of oil delivered during the compression stroke from the working chamber 44 into the working chamber 2 I, the bolt 8 carries a lateral aperture 56, which is passed over and closed by the lower face of the distributing piston I2 during the suction stroke of the bolt 8, whereupon it performs its delivery stroke. In order that oil cannot be sucked back into the working chamber H from the pressure passage 29, 29 at the commencement of the suction stroke of, the distributing piston I2, as long as the pressure passage is still open, a spring-loaded check valve 6| is provided in the part 29' of the pressure passage. This also prevents oil from being delivered through the dropnozzle 35 before the overflow aperture 56 is closed by the. distributing piston I2 during the latters compression stroke. Except for the above described details, the pump unit illustrated in Fig. 3 is of exactly the same design as that illustrated in Fig. 1. It works in the following mannerr The bolt 8 moves downwards out of the position illustrated at the beginning of the compression stroke. The distributing piston I2 held fast by the regulating screw 53 is drawn out of the blind bore I9., If there should be produced a greater degree of vacuum in the working chamber 2|, the check valve 27 will open and oil will flow into the working chamber 2! through the passages 23, 24, 25, and 26, while the check valve BI in the pressure passage 29' remains closed. As long as the control edge 48 of thebolt 8 leaves the suction passage 41 free, oil is forced 'out of the working chamber 45 through the passage 41. After the closing of the passage 41, the oil is forced out of the working chamber 45, after the lifting of the check valve 27, through the connections 23, 24, 25, and 26 and into the working chamber ii of the distributing piston. In the meantime, however, the distributing piston I2 has moved above the lower edge 62 of the lateral aperture 56 of the supply piston 8, and the oil therefore flows through the overflow aperture 56 into the storage vessel of the pump housing 31, lubricating the driving parts.

During the suction stroke of the bolt 8, negative pressure is first produced in the working chamber 44, but owing to the check valve 2'! this cannot extend to the working chamber 2| which is full of oil. After the cavity 51 has come into communication with the part 29' of the pressure passage, the distributing piston I2 slides over the edge 62 and, towards the ends of the suction stroke of the bolt 8, forces the oil enclosed by it in the working chamber 2| to the drop nozzle '35 by way of the pressure passage 29, 29' and the check valve 6|. From the drop nozzle the oil drops into the bowl 36, from which it flows to the working chamber 34 of the delivery piston Ii. What is claimed is: v '1. A lubricating pump comprising a pump housing, a drive member therein, at least one pump unit mounted in said pump housing, each pump unit including a body, an intake piston mounted in the body and in driving connection with the said drive member and driven in reciprocatory movement, means connected to the body and providing a working space for the said intake piston, said pump unit body having an inlet bore into the said working space, said intake piston having a cylindrical bore, a distributing piston mounted in the said cylindrical bore, an adjustable abutment in the said housing, which. coacts with the said distributing piston to press the same inwardly into the said cylindrical bore when the said intake piston is moved toward the said abutment, a channel in said intake piston extending from the said working space to the said cylindrical bore through which the lubricant is forced from the said working space to the said cylindrical bore, a feed piston "provided inthe body for said feed piston, a lubricant :line' fromv the-said cylindrical bore to the last-mentioned working space through which. the

lubricantis conveyed. in measured quantities. to

the-.saidfeed .piston, anda-lubricant outlet in connection with the last-mentioned working space through which the said feed piston ejects the lubricant.

-2..A lubricating pump according to. claim 1,

in which the said distributing piston. is secured 4. Alubricating pump according to claim 1, in: which the cylindrical bore is providedwith. a

discharge opening for excess lubricant whichis closed by the said distributing piston at the beginning. of its feed stroke.

5. A lubricating pump according to claim. 1, in which the lubricant line between the cylindrical bore and" the last mentioned working space includes a check valve and a drop nozzle.

6. A lubricating pump according to claim .1,

.in'which the lubricant line includes a cavity in the said intake piston communicating with the said cylindrical bore, a drop nozzle in the said line, and the body of the pump unit having a channel which leads from the said intake piston to the said dropnozzle and which. also forms a. "pa-rtof the lubricant line between the said cylin idrical: bore and the last mentioned working space, the said cavity and the last mentioned channel being'arrahged so that they come into registra-- tion with each other only toward the end of the suction stroke of the said intake piston.

'7. A lubricating pump according to claim 1, in which the said feed piston is arranged so that it crosses the lubricant line between the said cylindrical bore and the last mentioned working I space, and the'said feed piston having a groove which controls the flow of lubricant through the said line.

8-. A lubricating pump according to claim 1,

in which a check valve is positioned in the chann'elin the intake'piston extending from the first 'mentioncd working space to the said cylindrical bore.

9-. A lubricating pump according to claim 1,.

in which the said intake piston and the said feed, piston are arranged parallel to each other and connected with each other at their upper ends.

10. A lubricating pump according to claim 1, in which the pump unit body has a cylindrical bore for receiving the said intake piston, said bore having a cavity which forms an extension -of the Working space of the intake piston, a

channellin. the said intake piston terminating in a cavityat the periphery of the said intake piston, the two mentionedcavities periodically registering witheach otherfor the control of thecommunication between the first mentioned working space for the intake piston andthe cylindrical bore whichreceivcs-the distributing piston.

11. Alubricating pump as claimed inclaim .1, inwhich means is provided in the lubricant line for controlling the passage of the lubricant to the lubricant outlet, said means comprising a spring loaded piston traversing theline adjacent the outlet.

.12. Alubricating pump asclaimed in claim .11, in which av projection is provided, on the lower end. of the intake .piston and. cooperates with. the

spring loaded. piston to insure of operation'of the latter in. event of spring failure.

13. A. lubricating pump comprising a: pump housing, a drive member therein, a pump unit comprised in part by a body mounted. in said housing and having a pair of piston receiving bores therein, said pump unit body having .a pressure passage extending from the first bore through the second bore, a delivery-piston reciprocable within the second bore and controlling the flow of fluid therethrough, an intake piston reciprocable within the first bore'and having an'axial cylindrical bore therein, a port adapted to communicate said axial cylindrical bore with the inner end of the pressure passage in the pump body and a groove adapted to communicate the axial bore with a source of fluid lubricant,

said intake piston being driven in reciprocatory' movement by' said drive member, a distributing piston reciprocable Within the axial cylindrical bore in the said intake piston and adapted. to

REFERENCES CITED The following references are of record'in'the file of this patent:

UNITED STATES PATENTS Number Name Y Date- 1,564,294- Swanberg Dec. 8, 1925 1,790,728 Splain Feb. 3, 1931 2,037,434 Pfauser Apr. 14, 1936 2,144,748 Arnold Jans24, .1939 2,231,666 Golber Feb. 11, 1941 2,326,958 Marais Aug. 1'7, 1943 2,362,365 Evans Nov. 7, 1944

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