Патент USA US2135563код для вставки
NOV. 8, 1938. E_ w_ DAV1$ 2,135,563 LUBRICATING APPARATUS Filed March 11, 1931 3 4 Sheets-Sheet l gm 1+3175 20 262% @s Nov. 8, 1938. E, wupAvls 2,135,563 LUBRI CATING APPARATUS Filed March 11, 1931 4 Sheets-Sheet 2 W1» M Q raj )776 gm @M. ? I my?‘ Nov. 8, 1938. E. w. DAVIS 2,135,563 LUBRICATING APPARATUS Filed March 11, 1931 _ 4 Sheets-Sheet 3 40 ‘110 WIIl! ll: III. ____ ____ , .a 7 m_ . T / ,..| .. @W w .\. m w . __6 a pay a 1 m g1 1 m m H w 1 68% 6 \/\< // ‘ 0 m 9 38 A?) (dial/e3; 19%‘ 2¢C 5M g’ @3 Nov. 8, 1938. E. w. DAVIS 2,135,563 LUBRICATING APPARATUS _ Filed March 11, 1931 2/. 4 Sheets-Sheet 4 (gr/$6525 larpaua's (By “Ma/n40] 6 Patented Nov. 8, 1938 2,135,563 STTES PATENT QFFlCE 2,135,563 LUBRICATING APPARATUS Ernest W. Davis, Oak Park, Ill., assignor, by mesne assignments, to Stewart-Warner Corpo~ ration, Chicago, 111., a corporation of Virginia Application March 11, 1931, Serial No. 521,748 21 Claims. (Cl. 184-7) My invention relates to lubricating apparatus being had to the accompanying drawings, in and is more particularly concerned with an im which _ provement in centralized lubricating systems. Fig. 1 is an elevational View of my improved My invention further relates to an improved lubricating system, showing the pump mechanism 5 pump mechanism for use with a centralized lubri and a plurality of resistance units of the type cating system of this type. The lubricating sys preferably employed with this system and which tem of my invention is primarily adapted for use with industrial machinery having a large number of bearings to be lubricated, bearings 10 that require lubricant at regular intervals and in different proportions. To accomplish this pur pose, resistance units of different sizes are em ployed at each of the bearings to segregate the desired amount of lubricant for each respective 15 bearing. The principal object of my invention is to provide an improved lubricating system of the type wherein resistance units are employed at the bearings to allow the desired amount of lubricant 20 to ?ow to each respective bearing and which are arranged to allow to each bearing a measured discharge of lubricant regardless of the viscosity of the lubricant. A further object of my invention is to provide an improved automatic pump mechanism for use with a lubricating system of this type. A further object is to provide an improved automatic pump mechanism having timing means therein which regulate the duration of the dis 30 charging period of the pump according to the viscosity of the lubricant. A further object is to provide an automatic pump which will discharge the same amount of lubricant to the bearings regardless of any change ' in temperature which may affect the viscosity of the oil or regardless of any other reason whereby the viscosity of the oil is changed. A further object is to provide an improved pump of this type capable of forcing lubricant 40 to the bearings for intermittent periods under an extremely high pressure and relieving the pres sure in the line during the intervening periods. A further object is to provide an improved mechanism of this type having a pair of continu ' ously operating pumps arranged to cooperate to force lubricant to the resistance units adjacent the bearings at regular intervals and under an extremely high pressure. ‘ Still another object of my invention is to pro vide an improved pump mechanism of this type which is comparatively simple in construction, yet extremely rugged and durable, and which will not easily become out of order. Other objects and advantages will be more ap 55 parent from the following description, reference are shown in cross-section; Fig. 2 is a vertical sectional view of the pump mechanism, taken on the line 2—2 of Figs. 1 and Fig. 3 is a vertical sectional view of the pump mechanism taken on the line 3—3 of Fig. 2, with the drive pulley omitted which corresponds with the view taken generally on the staggered line 3—3 of Fig. 4; and 15 Fig. 4 is a. top plan view of the pump mech anism, with the cover partially broken away to illustrate more clearly other parts. In the drawings; in Fig. 1 I have shown a fragment of a machine l0 which may be of any 20 desirable type of industrial'machine having a plurality of moving parts and bearings to be lubricated. A pair of these bearings l2, l2 are shown in cross-section supporting a pair of hori zontal shafts l4, It. A combined pump and 2.’; reservoir unit A is shown mounted in any con venient place on the machine l0 and securely at tached thereto by bolts IS. A lubricant conduit [8 may extend from unit A to the various bearings upon the machine I0 31» to be lubricated and terminate in body members 20 and 2| within which the resistance units are mounted. The resistance units employed in this system may be of the general type shown in the application of Charles F. Raisch, ?led August 3.3 26, 1929, and bearing Serial Number 388,332, and will not be described herein in any great detail. Generally speaking, these resistance units may comprise a body 20 having a central axial bore therein. The lower end of the bore is threaded '40 to receive a resistance plug 24. A sealing mem ber 26, adapted to cooperate with a bushing 28 to connect the body 20 to conduit I8, is also lo cated in said bore. The sealing member 26 is arranged to support a check valve 30. The 45 details of all of these parts are more clearly dis closed in the above-mentioned application. The body member 2| is similar in all respects to the body member 20 except that the body memher 2| carries a member 32 whereby a T connec tion may be made in the conduit line Ill. The resistance units, generally speaking, are adapted to be of the desired size to permit discharge of lubricant at the desired rate to each particular 0 2 2,188,888 bearing when lubricant under a high pressure is forced through the conduit line I8. Referring now more particularly to the unit A, which comprises a combined ‘pump and reser voir unit, I provide a hollow base casting 38 hav ing lugs 38 through which the bolts I8 pass to secure the unit to the machine I8. An inverted cup-shaped cap member 48, positioned upon the top of base 38, effectively closes its upper end 10 and is fastened thereto by means of cap screws Referring now more particularly to Figs. 2 and 8, a pair of pump mechanisms 44 and 48 are provided, one of which, 44, is adapted to pump 15 lubricant to the bearings, and the other, 48, is adapted to pump lubricant vto a control device hereinafter to be described. Both of the pump mechanisms are carried by a unitary frame mem ber 48 which is secured to the under side of 20 cap member 48 by means of bolts 4I. As most clearly shown in Fig. 3, each pump unit comprises a plunger 88 engaged by an en larged stem 52 journailed in a plurality of lateral ?anges 54 and 56 of the frame member 48. The plunger 58 of pump 44 is re'ciprocated in the ver; tical bore 58 of a cylinder block 88 which is screw threadedly mounted in a lower lateral ?ange 82 of the frame 48. A pair of inlet ports 84 in the cylinder block communicate with bore 58. A 30 spring-pressed valve 88, which normally closes the lower end of bore 58, is located in an enlarged chamber 88 in the cylinder block 88 and the lower end of this chamber is closed by a screw extends from the cap at one end where a pulley I I2 is mounted thereon. Pulley I I2 may be driven by means of a suitable belt I I4 from any rotating part of the machine I8, such part being deter mined from the particular construction and lubri cation requirements of the particular machine upon which the lubricating‘ unit A may be 10 As most clearly shown in Fig. 2, cam I8‘! is an eccentric situated above the upper end of plunger stem 82 of pump 44 and as it rotates, forces plunger 58 down in bore 88, and spring ‘I9, situ- _ ated between cap ‘I8 and ?ange 82, forces plunger stem 82 upward and also raises plunger 88 in bore 88. Pump 48 may be similarly driven. How ever, in this embodiment of the invention it has been shown as a gravity operated pump plunger stem 52 having a disk II5 secured to its top end and engaged by cam I88. The cam raises the plunger stem and permits spring 95, positioned between ?ange 82 and cap 98 attached to the top of plunger 58, to raise the plunger in the cylinder 25 block 82. As the cam revolves, disk II 5 drops from the edge II8 of the cam and urges plunger 58 downward. Means for adjusting the length of this stroke is provided in the form of a limit stop member I28 screw-threadedly supported in cover 30 48. The position of the stop member may be varied by loosening lock nut I22 and inserting a screw-driver in slot I24 and moving the stop member up or down. plug ‘I8. A conduit "I2 is connected to the cylinder block 88 by a connector bushing ‘I4 through which the conduit is in communication with chamber 88. A cap member 18 is attached to the upper end of plunger 58 on a reduced end thereof and contacts 40 the stem 52. A compression spring ‘I9, arranged between cap ‘I8 and ?ange 82, holds the plunger 58 in engagement with the enlarged stem 52. Pump 48 is generally similar to pump 44, be ing provided, however, with a plunger 58 of a rela 45 tively small diameter which reciprocates in a bore v88 in cylinder block 82. A slotted opening 84 through one wall of the cylinder block provides an inlet port to the bore 88 which is closed at its lower end by a ball check valve 88 located in 50 anenlarged chamber 88 in the lower end of the block. These cams are mounted. 42. . 35 I81 and I88 are provided. pinned to a drive shaft I89. Shaft I89 is Jour nalled in a pair of bearings .I I8 in cap 48 and The cylinder block is screw-threadedly mounted in a supporting member 98 which has a reduced end portion adapted to fasten into a tapped bore 92 in ?ange 82. A conduit 98 is 55 secured in member 98 by a suitable connector bushing 91 and communicates through passage way 99 with chamber 88. A cap member 98 is connected to the upper end of plunger 58 on a reduced end thereof and con 60 tacts with stem 48. A compression spring 95, ar ranged between cap 98 and ?ange 82, holds the plunger 58 in engagement with the lower end of the enlarged stem 48. A pair of vertical side walls I88‘ connect ?anges 54 and 82 of the frame 48, leaving more or less rectangular openings in the frame casting through which lubricant may reach the pumps 44 and 48. These openings are closed by suit able strainers I82 which are similar in all respects 70 and preferably comprise a wire mesh screen I84 supported by a pair of rectangular frame mem bers I85 and fastening screws I88. Pumps 44 and 48 may be actuated in a number of different ways, and in the embodiment of the 75 invention shown in the drawings a pair of cams As previously mentioned, pump 44 will force lubricant into conduit 12 which extends from cylinder block 88 to the head member I28 of a timing device or temporary reservoir I28, being connected thereto by a suitable connector bushing I38. Lubricant discharge conduit I8 extends 40 through a wall of cover 48 and is attached to head member I28, suitable lock nuts and bushings be ing provided where the conduit passes through the wall of cover 48. As thus far described, it will-be obvious that lubricant under pressure will 45 be continuously pumped to the upper end of the combined timing or reservoir unit I28. Pump 48 is connected through conduit 98 with a lower cap member I32 of reservoir I28 by a suit able connector bushing I34. A reciprocable pis 50 ton I38 is mounted in reservoir I28 and comprises generally a cylindrical body member I38 having a reduced upper end portion I48. An inverted cup leather washer I42, a retaining member I44, and an upwardly turned cup leather washer I48, are 55 all mounted upon the reduced end portion I48 which is upset at its upper end to securely fasten these elements against a shoulder I". A cham ber I52 in body member I38 is closed‘ at its lower end by a plug member I58. A valve I54 is posi 60 tioned in chamber I52 and extends upwardly through an aperture I58 in the upper end of pis ton I38. The upper end of the valve is hemi spherically shaped to close an outlet I58 in the upper Wall of head member I28. Valve I54 has 65 a reduced threaded lower end. I88 upon which a ?anged member I82 is secured. A spring I84 is carried by the ?anged member I82. A pipe union I85 is secured between the lower cap I32 and a body member I88. The member 70 I88 is provided with a vertical bore I 88, the upper end of which is enlarged and V-threaded as shown at I18. A tapered wall "I connects the bores and provides a seat for a gravity oper ated ball check valve "2. A threaded plug I13, 75 3 2,136,563 arranged at the lower end of a bolt I14 which is mounted in cap 40, is arranged to be screw threadedly mounted in the tapped bore I10. way I'll serves to govern the period of time during which lubricant is being pumped to the bearings under high pressure in view of the fact Bolt I‘I4 carries at its upper end a knurled > that the lubricant in the lower end of reservoir handle I15 and a lock nut I18. The V-shapecl I28 allows piston I38 to descend at a rate of threads III) are arranged to have their pointed speed governed entirely by the rate of ?ow of the edges removed so that when plug I13 is screw lubricant through the spiral passageway I ‘H of threadedly mounted in the threaded bore a spiral the resistance unit. With the timing device thus passageway I‘I'I will be formed between these provided, it can readily be seen that lubricant ll pa1't-s.,,_By this arrangement a resistance unit, of different viscosities may be placed in the reser 10 similar-to those employed at the various bearings, voir A, and with lubricant of any viscosity the yr is provided. The distance that resistance plug I13 is screw threaded into tapped bore III! will determine the amount of lubricant of a certain viscosity which will pass through the timing valve thus provided in a given period of time. It is obvious that the higher the viscosity of the lubricant, the more time will be required for a de?nite quantity of lubricant to pass through the valve. In operation, my improved pumping device may be located upon an industrial machine which has bearings to be lubricated and which has a moving element adapted to drive shaft I88 by means of belt H4 and pulley H2. The two pumps in reservoir A will thus be continuously operated through the medium of cams I81 and I08. Assuming that the hollow base casting 36 is ?lled with lubricant, it will thus be evident that pump 44 will pump lubricant through conduit 12 into the upper end of auxiliary reservoir I28 and pump 46 will pump a smaller quantity of lubricant into the lower end of reservoir I28. Li Lubricant pumped into the upper end of the reservoir may escape through opening I58 but as a lubricant pressure is built up in the lower end of the reservoir, piston I38 will gradually be raised until valve I54 closes the outlet I58 in 40 the upper end of the reservoir. At this time lubricant being pumped through conduit ‘I2 will be forced out through con‘duit I8 to the various ?ow measuring devices, such, for example, as 20 and ‘2|. Due to the fact that the lubricant is being pumped under an extremely high pressure, lubricant will be forced through the resistance plugs of the units 20 and 2I at a de?nite rate of travel. _As the conduit I8 and all of the measuring units become ?lled with lubricant, the lubricant pressure in the upper end of reservoir I 28 will serve to force lubricant through the measuring units, the pressure gradually being built up to a point where it is suf?eient to cause piston I38 to descend. Valve I54, however, will remain seated in opening I58, due to the lubricant pres sure, until spring I64 engages the-upper end of chamber I52, and the spring will be compressed until the lubricant pressure in the upper end of the chamber is su?iciently great to force valve I 54 down, at which time, due to the fact that spring I64 has been compressed, the valve stem will spring downwardly, thus sharply and quickly opening port I58, and allow the lubricant to ' over?ow therethrough from the upper end of the chamber, thus relieving the pressure in the line I8. During the period of time in which valve I54 closes opening I58, the lubricant being pumped into the lower end of reservoir I28 ?ows through union I65 into the interior of member I66. As the amount of lubricant increases the lubricant raises check valve "2 and flows through the spiral passageway I" of the resistance unit to 75 escape. The rate of flow through the passage amount of lubricant forced to the bearings by the pump mechanism will be the same, due to the fact that by the action of the timing resist ance unit lubricant of a high viscosity will con sume a longer period of time in allowing valve I 54 to open than would be the case with lubricant of a lower viscosity. - Due to this action it is also obvious that, re gardless of the temperature of the room in which the machine is operating, the amount of lubri cant reaching the bearings in di?erent temper atures will always be the same. Means in the form of a safety valve must be provided in conduit ‘I2 to prevent an excessive high pressure in the conduit line I8 and to this end a safety valve I80 is provided in the chamber 68 of cylinder 60. The safety valve may com prise a housing I8I in which a one-way check valve I 82 is mounted. A cover I83, screw threadedly mounted on the end of housing I8I, has an opening I84 therein and serves both as a seat for spring I85 and a means of escape for the overflow of lubricant. It will of course be under stood that this check valve may also be located in the upper end of reservoir I28. From the detailed description of the operation of my improved apparatus, it will be apparent that a certain sequence of operations will take place at predetermined timed intervals. First, 40 the pump 44 will operate ineffectively merely to discharge oil through the outlet port I 58 and there will be no pressure upon the conduit sys tem. Second, when the pump 46 has completely ?lled the lower end of the reservoir of the con trolling device su?iciently to raise the valve I54 to close the port I58, lubricant will be forced under pressure to the conduit system and flow 45 through the measuring units at the bearings. As soon as lubricant is ?owing through these units and the pressure is built up sufficiently to force lubricant to flow through the timing re sistance unit in the reservoir, the controlling valve assembly I36 will be forced downwardly, and after a. period of time, governed entirely by the resistance unit in the reservoir, the assem bly will open valve I54, thus relieving the pres sure upon the entire conduit system and allow ing lubricant to flow through port I58 in the reservoir. 60 By adjusting the position of member I28 the length of the stroke of pump plunger 50 of pump 46 may readily be controlled and the frequency of the high pressure lubrication may readily be increased or diminished._ > When the apparatus of my invention is directl . connected with a normally moving part of a machine to be lubricated, it will of course be apparent that the bearings will be supplied with lubricant in accordance with the speed and time of operation of the machine. While I have illustrated and described a speci?c embodiment of my invention, it will be under stood that changes and modi?cations may be made in the details of construction, and I do not 75 4 9,188,588 I V wish to be limited to the precise details shown ‘lubricant from said reservoir to said conduit sys but desire to avail myself or all"ch'a;nges within the'scope of the appended claims. I claim as my invention: 1. Lubricating apparatus comprising a. lubri-‘ cant container, a conduit extending therefrom to hearings to be lubricated, an ‘auxiliary reservoir mounted in said container, said auxiliary reser voir having an over?ow opening therein, a piston in the auxiliary reservoir, means for pumping lubricant into the reservoir on the lower side of said piston to move said piston to close said over ?ow opening, means for forcing lubricant through said auxiliary reservoir into said conduit after the over?ow opening is closed, and a control unit associated with said pumping and forcing means for governing the period during which lubricant is discharged to said conduit. ' tem, and means operable periodically to render said pumping mechanism effective to supply lubricant under pressure to said conduit system,~ the duration of the e?ective periods oi! operation being dependent upon the viscosity of the lubri cant. i - 8. A centralized lubricating system adapted to deliver to each of a plurality of bearings a pre determined quantity of lubricant regardless of 10 theviscosity thereof, comprising a lubricant res ervoir, a plurality oi! bearings, conduits extend ing from said reservoir to said bearings, metering units adjacent the bearing ends 01' said conduits, a continuously operating pump in said reservoir, and means in said reservoir operable independ ently of the rate of ?ow of lubricant to said metering units for controlling the duration oi the 2. A pump mechanism comprising a pair of " discharge of said pump into said system in ac continuously operating pumps, each of said cordance with the viscosity of the lubricant being 20 pumped. pumps connected with a di?erent end of an aux iliary lubricant reservoir, a valve in said reser voir, one or said pumps normally pumping lubri cant into the lower end of said auxiliary reser voir to raise said valve to close an over?ow port, the other continuously discharging lubricant into an upper chamber in which said over?ow port is located and when said port is closed to a lubri cant conduit under high pressure, and means in cluding a ?ow resistance means associated with said ?rst pump for controlling the period of dis charge to the lubricant conduit. 3. A pump mechanism comprising a pair of continuously operating pumps, each of said pumps connected with a di?erent end of an auxiliary lubricant reservoir, a valve in said reservoir, one 9. In a centralized lubricating system having a ' plurality of bearings to be lubricated, a plurality of resistance units, one associated with each of the bearings and constructed and arranged for 25 controlling the ?ow of lubricant thereto, a lubri cant reservoir, conduits extending from said res ervoir to said resistance units, a continuously operating pump for transferring lubricant from said source to said conduit system under pres 30 sure, and means in said reservoir for relieving the lubricant pressure in said conduit system after the lubricant has been supplied thereto for a period determined by the viscosity of the lubricant. 35 ' 10. In a centralized lubricating system includ ing a plurality of bearings to be lubricated, a ?ow resistance unit mounted at each bearing, a lubricant reservoir, a conduit extending from said reservoir to‘ said ?ow resistance units, a 40 pump mechanism in said reservoir and having its discharge port connected to said conduit, and means operable independently of the rate of ?ow through said resistance units and responsive to and means including a ?ow resistance means the viscosity of the lubricant in said reservoir 45 associated with said ?rst pump for controlling for controlling the duration of the discharge of the period of discharge to the lubricant conduit. said pump mechanism into said conduit. 4. A pump for a centralized lubricating sys 11. In a centralized lubricating system hav tem comprising an oil reservoir, means for eifect- ' inga plurality of bearings to be lubricated, a ing periodic discharges of oil from said reservoir, flow resistance unit mounted at each bearing, a 50 and means responsive to the viscosity of the oil lubricant reservoir, a conduit extending from in said reservoir for regulating the frequency of said reservoir to said ?ow resistance units, and said periodic discharges. ' v a pump mechanism constructed and arranged 5. A lubricating system comprising a lubrican periodically to pump lubricant to said bearings container, periodically operating means for creat under high pressure, said mechanism including 55 ing intermittent pressure periods in said system, means operable independently of the rate oi’ ?ow of said pumps normally pumping lubricant into the lower end of said auxiliary reservoir to raise said valve to close an over?ow port, the other continuously discharging lubricant into an upper chamber in which said over?ow port is located and when said port is closed to a lubricant con duit under high pressure, said pump adapted to open said over?ow port after a period of time, and means responsive to the viscosity of the lubri cant in said container for controlling the dura tion of and intervals between the cycle of opera tion of said periodically operating means. of lubricant to said resistance units and respon . 6. In a lubricating system a unit for e?ecting the discharge of lubricant from a central reser voir to the system comprising a pump, a conduit connecting said pump with the system, a valve for controlling the discharge of lubricant from said pump to said system, a lubricant circulating system operating responsive to the viscosity oi! the lubricant in the reservoir, and means respon sive to the differential pressures in said conduit and said lubricant circulating system for con trolling said valve. 7. A lubricating system comprising a reservoir, a conduit system for distributing lubricant to a plurality or bearings, a continuously operating pump mechanism for intermittently supplying sive to the viscosity oi.’ the lubricant to control the duration of discharge of said pump mecha nism to 'the bearings. 60 12. A centralized lubricating system adapted to deliver a measured quantity oi’ vlubricant to each of a plurality oi’ bearings regardless of the viscosity of the lubricant, comprising a lubricant reservoir, a plurality of bearings, conduits ex 65 tending from said reservoir to said bearings, a ?ow resistance unit at each of said bearings, a continuously operating pump receiving lubricant from said reservoir, a valve affecting ?ow from said pump to said bearings, means for opening 70 said valve, said means including a resistance unit whose e?ect is dependent upon theviscos ity of the lubricant, and means for closing said valve. 13. A lubricating system comprising an oil 75 2,135,568 reservoir, an oil line, a plurality of resistance units associated with said line for apportioning the lubricant supplied thereto among a plurality of bearings, continuously operating automatic means for intermittently discharging oil from said reservoir to said oil line, and means respon sive to the viscosity of the oil in said reservoir for controlling the duration of the periods dur ing which oil is discharged into said line. 14. A centralized lubricating system including a plurality of bearings to be lubricated, meter ing units associated with said bearings for ap portioning the supply of lubricant among said bearings in accordance with their respective [5 requirements, a lubricant reservoir, conduits ex tending from said reservoir to said metering units, a continuously operating pump mecha nism in said reservoir for supplying lubricant to said metering units at a high pressure, a. valve for by-passing lubricant from said pumping 5 ing, a branched distribution conduit system leading to said bearings, a source of lubricant pressure, means for periodically admitting said lubricant pressure to said system during oper ation of the mechanism, and temperature con trolled means for regulating the duration of the periods of admission. 18. A central lubricating installation for a plurality of bearings of a mechanism compris ing, a branched distribution conduit system lead 10 ing to said bearings, a source of lubricant pres sure, means for periodically admitting said lu bricant pressure to said system during operation of the mechanism, and lubricant viscosity con trolled means for regulating the duration of the 15 periods oi.’ admission. ‘ 19. In lubricating apparatus, a combined pump and reservoir mechanism comprising, a hollow base casting, a closure cap therefor, a pump sup porting frame suspended from said cap, pump 20 mechanism to said reservoir, a second continu means supported on said frame, a secondary res ously operating pump, means operated by said ervoir in said base casting, a conduit extending from said pump means to said secondary reser voir, means in said secondary reservoir and oper ated by lubricant supplied by said pump means to control the length of the intervals between dis charges of lubricant from said secondary reser second pump for closing said valve, and means dependent upon the viscosity of the lubricant for determining the length of time said valve is maintained closed and ‘thereby determining the period during which lubricant is supplied under pressure to said metering units. ' 15. A centralized lubricating system including a plurality of bearings to be lubricated, measur ing devices associated with said bearings, a cen tral reservoir, conduits extending from said res ervoir to said measuring devices, a pumping mechanisminsaidreservoir, 'said pumping mech anism operating continuously at a uniform speed and having means for periodically discharging lubricant to said measuring devices under high pressure, and means responsive to the viscosity of the lubricant for varying the duration of the periods during which lubricant is discharged to said devices. 16. In a centralized lubricating system, the combination of a lubricant reservoir, a plurality of bearings to be lubricated, a ?ow metering unit at each bearing for controlling the ?ow of lubri cant thereto, conduits connecting said ?ow metering units and said reservoir, a cylindrical chamber in said reservoir having a by-pass open ing therein, a pair of pumps in said reservoir, said pumps being connected to opposite ends re spectively of said cylindrical chamber, a valve in said chamber operable to close said by-pass, valve operating means reciprocable in opposite directions by the pressure of the lubricant sup plied by said pumps respectively, and a high re sistance bleed passageway leading from the end of said cylindrical chamber opposite said by pass opening to said reservoir, whereby the rate of ?ow of lubricant through said restricted pas sageway will control the length of the period during which said valve is closed. 1'7. A central lubricating installation for a voir, and a control means connected to said secondary reservoir and responsive to the viscosity of the lubricant for determining the duration of 30 the discharge period. - 20. A lubricating apparatus comprising, a con tainer for lubricant, conduits extending there from to a plurality of bearings to be lubricated, a pair of continuously operating pumps in said 35 container, a valve closing a by-pass from the dis charge side of one of said pumps to said container, a cylinder having one end thereof connected to the discharge side of said last named pump and having its other end connected to the discharge 40 side of the other of said pumps, a piston recip rocable in said cylinder in a position to have its opposite faces acted upon respectively by the dis charge from said pumps, a lost motion connec tion between said piston and said valve, and a 45 high resistance permitting escape of lubricant from said cylinder, said piston, said cylinder, and said resistance vent constituting means for con trolling the duration of the periods during which said valve is closed, thereby to control the dura 50 tion of the periods during which lubricant is sup plied through said conduits to the bearings to be lubricated. 21. A pressure supply installation for a system for the lubrication of the bearings of automobiles 55 comprising, a conduit system for supplying lu bricant to the bearings to be lubricated, a source of lubricant pressure, means for periodically ad mitting said lubricant pressure to said conduit sys tem during operation of the mechanism, and lu 60 bricant viscosity controlled means for regulating the duration of the periods of admission. plurality oi’ bearings oi’ a mechanism compris- , ERNEST W. DAVIS.