US2448583A - Lubricant injector - Google Patents

Description

Sept. 7, 194s. A, P, Fox 2,443,583

LUBRIGANT. INJECTOR Filed March 51. 1945 l wm.

FIG 14.

FIG.|.

Patented Sept. 7, 1948 LUBRICANT INJECTOR Alexander P. Fox, University City, Mo., assignor to Lincoln Engineering Company, St. Louis, Mo., a corporation of Missouri Application March 31, 1945, Serial No. 585,834

4 Claims. (Cl. 184-7) This invention relates to injectors, and with regard to certain more specific features, to lubricant injectors for delivering measured charges.

Among the several objects of the invention may be noted the provision of a compact form of lubricant injector responsive to pressure for consistently delivering accurately measured charges; the provision of an injector of the class described which due to its small size may conveniently be located in multiple on a manifold or the like, or which may have individual units fastended at convenient points on a machine, the bearings of which are to be lubricated; land the provision of an injector of this class which is reliable in operation and economical to make. Other objects will be in part obvious and in part pointed out hereinafter.

The invention accordingly comprises the elements and combinations of elements, features of construction, and arrangements of parts which will be exemplified in the structures hereinafter described, and the scope of the application of which will be indicated in the following claims.

In the accompanying drawings, in which is illustrated one of various possible embodiments of the invention,

Fig. 1 is a plan view showing application oi.' two units of the invention to a common manifold;

Fig. 2 is a front elevation of Fig. 1;

Fig. 3 is an enlarged section taken on line 3--3 of Fig. 1;

Fig. 4 is an enlarged section taken on line 4--4 of Fig. 2, showing an injecting and reloading position of parts; and,

Fig. 5 is a fragmentary view similar to Fig. 4, but showing the injecting piston biased to an initial position and the metering piston in metering action.

Similar reference characters indicate corresponding parts throughout the several views of the drawings.

The injector of .the present invention is adapted Ifor use as part of P known type of lubrication system which includes a high-pressure lubricant pump dispensing lubricant at xed intervals through a supply line and including automatic means for relieving the pressure in this supply line between said intervals. For example, the pressure in the supply line may be raised for short periods at intervals of an hour or so. The pressure raising and relieving cycle is determined by suitable means such as a time clock or the equivalent. Details of these features are not described herein since they form no part of the invention per se, are well-known, and onlyA form the environment for the present invention.

The invention per se refers to an injector mechanism which at intervals receives its supply from said supply line,A accurately measures it and injects it to the apparatus which is being supplied,

for example Ia bearing, or bearings. The injected quantitiesbeing rather small, it has been difficult with the injectors used heretofore to maintain their accuracy, and the present inven- .tion accomplishes this. With many classes of machinery, accurately injected lubrication is highly desirable to provide `a continuous supply of lubricant without an oversupply.

0ne dimculty with the prior injectors was that they used only one injector piston for metering and for injection. According to the present invention, the injection and the metering functions are in separate elements coordinated in a novel manner to produce positive, accurately metered injections, thus permitting of varying the metered quantities with the same injector piston and travel.

Referring to the drawings, numeral I indicates a pressure manifold having a passage 3 plugged at one end at 5 and having an inlet 1. This inlet is connected to the supply line above referred to but not shown. At 9 is shown a bore which is threaded at the top II for receiving an injection. element of one injector. This bore 9 has a cross connection I3 with a second bore I5, the latter being threaded at I1 for receiving a metering element of said injector. Bore I5 forms an auxiliary or metering chamber. A side opening in bore I5 which is used for access in making the bore I 3 is plugged by a cap screw I9. This cap screw I9 also holds a spring clip detent 2I, to be referred to later. It will be understood that the manifold I may be made to accommodate an indenite number of the units to be described.

Optional openings 23 are used for mounting the manifold as desired.

In the bottom of the bore 9 is a resilientpacking ring 22 and spaced from this is placed a second packing ring 25. The spacer is an open cage ring indicated generally by numeral 21. This ring consistsof two sets of annular washer-like portions 29 spaced by axial extensions 3i located at intervals. This cage ring '21 admits a radial ow of lubricant between the packing rings 22 and 25.

Sliding within the packing rings 22, 25 and the cage ring 21 is a hollow injector piston or plunger 33 having an end 35 responding to pressure from the inlet 3. This injector piston is made hollow from'its rear end by boring it axially as shownv partment carries a spring 53 which reacts between the thrust washer 49 and the upper end of the compartment 5I. Threaded into-the upper end of said fitting 45, and within the confines of the end of spring 53, is a check valve assembly 55. This admits of outward flow but checks against return flow. In the compartment 5I is also a shoulder 51 for limiting the movement of the thrust washer 49 when the piston 33 is moved by pressure from the inlet 3.

In the auxiliary bore I5 is a shoulder 59 for seating a packing ring 6I over which is a confining washer 63. This washer 63 is held in place on a shoulder by a screw fitting threaded into the manifold opposite the bore I5. Through the assembly 6I, 63, passes a metering piston 65 having a reduced stem 61 which extends from a shoulder 66 at its rear end. On the` shoulder 66 rests a thrust washer 69 for receiving the thrust of a spring 1I. The spring 1I seats at the upper end against a shoulder 13 in the fitting 15. A shoulder 11 forms a stop for the thrust washer 69 and forms an ultimate limit to the motion of the metering piston 65. To the upper end of the member 15 is threaded a hollow cap 19 in which is an opening 3| accommodating a further reduced portion 33 of said stem 61. This reduced extension 33 acts as a telltale indicator. The inner surface of the cap 19 forms a movable stop for the shoulder 82 on stem 61 and thus adjustably limits the motion of piston 65 for movements less than maximum.

Exteriorly the cap 19 is serrated, as indicated at 95, for engagement by an indentation 81 in the spring detent clip 2l. As above stated, the spring 2l is held by the cap screw I9. Thus any predetermined threaded setting of the hollow cap 19 is maintained and it forms an adjustable stop for the motion of piston 65. A turned-in tab 90 on the clip 2l is engaged by a shoulder 9I on the cap 19 to prevent accidental screwing of the cap into a non-effective range, and to prevent its accidental removal.

Operation is as follows:

Upon admission of lubricant under pressure into the inlet 3, it impinges upon the exposed end of the injector piston 33, thus pushing said piston toward the check valve 55 (Fig. 4). The face 35 passes the cage ring 21, thus admitting pressure to the passages I3 and I5 and pushing the metering piston 65 up to the location shown in Fig. 4. During the stated movement of the piston 33, prior delivered lubricant is forced from the chamber 5I out to a suitable lubricant line threaded to the tting 45 at 89. This line passes to an individual bearing or the like. Thus a previously measured charge is delivered and the available space under the piston 65 is loaded with lubricant. The amount under piston 65 is measured by its displacement as determined by the setting of cap 19. The maximum adjustment is one under which the volume accommodated under metering piston 65 is more than the effective displacement of the injector piston 33. In figuring the effective displacement of the injector piston 33, it should be observed that this piston does not start its effective ejecting displacement until the lower edge of the groove 4I closes off the ports in the spacer 21. Up until that time material may return from the chamber 5I to the bore I5 beneath piston 65 (valve 55 closed); and only thereafter does the valve 55 open and injection take place. The maximum displacement of the metering piston is maintained greater than the displacement oi' the injector piston; in fact the displacement capacity of the metering piston can be again as great as the displacement of the injector piston, since the metering piston during each cycle cannot recharge any more lubricant than the injector piston displaces.

The return of the plunger 33 to its initial position is accomplished when the pressure to the inlet 3 is relieved by a suit ble means, as is known in this art. Incidenta ly, this may be manual or automatic. This allows spring 53 to push back the injector piston 33 to the position shown in Fig. 5, in which the passages I5, I3 are in connection with the chamber 5I through the hollow cage 21 and piston 33. At this time the metering piston 65 will be pushed down by its spring. In Fig. 5 it is part-way down and tending to fill the void left by movement of piston 33. Valve 55 is at this time closed as shown in Fig. 5. This re-charges the compartment 5I while discharging the lubricant from the bore I5. The above operation will again be repeated whenever pressure isv suitably increased in the inlet 3.

It is to be emphasized that the maximum volumetric displacement of the piston 65 is larger than that of piston 33. Under an adjustment for such maximum volumetric displacement of metering piston 65 (Fig. 4), the evacuated space left by return of the injector piston 33 is entirely lled by return action of the metering piston 65, even though a small amount of lubricant may escape from under piston 65 to the relieved inlet 3 before piston 33 disconnects passage I3 from said inlet.

By adjusting the hollow cap 19, the stroke of the metering piston 65 may be changed and consequently the volumetric displacement controlled by that piston. In Fig. 4 the adjustment is shown at the maximum. Downward adjustment of cap 19 will reduce the stroke of the metering piston `65 and hence the amount thatwill be accepted beneath it when lubricant is admitted. The adjustment may be varied from the maximum shown down to the minutest of metered charge. When the metered charge is less than maximum it is of course apparent that all of the evacuated space left by return of the injection piston 33 (for example from a Fig. 4 position to a Fig. 5 position) will not be infllled with lubricant. However, no air can get into this evacuated space because valve remains closed until plston 33 performs an injection stroke. Then upon the next injection stroke ofl the injector piston 33 the vacuous space will disappear, there being no air in it, and the metered charge, whatever its volume, will then positively be discharged through valve 55 which is at vthis time pushed open. From the foregoing it is obvious that with the metering piston adjustment set below the displacement capacity of the injector piston, no more lubricant can be displaced by the injector piston per cycle than the amount transferred from the metering chamber to the injector chamber below the valve 55. These points, taken in connection with the use of an auxiliary metering piston, instead of using one piston for metering and injection, constitute important4 advantages of the present invention from the viewpoint of accurate feed.

Another point of some importance to be observed is that even though the cap 19 be accidentally screwed down until the metering piston has no stroke whatever, the device under repeated cycling of the timer will continue to feed at least a minute quantity so that a bearing or the like connected therewith will not be-completely starved of lubricant. This is because when pressure is relieved in the inlet 3, the return action of the injector piston 33 will cut ol passage before all of the pressure in passage Il has leaked off. Thus when the groove 4| comes opposite the spacer ring Z1, a minute quantity of the lubricant under pressure will tend to move into the void left behind the returning piston 33 assisted by the vacuum created, thereby equalizing the pressure.

It may at this point again be stated that the reason for making the volumetric displacement of the metering piston 65 somewhat more than i the displacement of the piston 33 is so that at maximum adjustment the empty space left behind by the returning injector piston 33 will be completely fllled even though there may have vbeen a. slight return action by the metering piston 65 during the time that it takes the injector piston 33 to move across the ports in the ring 21,

assuming that pressure in the inlet 33V has beenv l. A lubricant injector comprising a chambered body having an inlet and a coaxial outlet, a check valve in the outlet, spaced annular resilient packing means within the body, annular huid-transmitting means spacing said packing means, a

hollow injector piston movable within the packing and spacer and having a solid face presented to pressure from the inlet and having a port on its other end communicating with said outlet, said piston having a peripheral communication from its hollow portion, means biasing said piston toward an initial position wherein said peripheral means is within said annular spacing means, an auxiliary chamber in said body, a movable metering piston in said chamber, means bias..

ing said metering piston to an initial position, a a.

iiuid connection from said auxiliary chamber to said hollow spacing means, whereby when said injector piston is moved against its bias by pressure from the inlet, iluid is forced from the inlet to said auxiliary chamber to displace the meter-l ing piston, and when lsaid first piston is biased toward its initial position by decrease in pressure in the inlet, its hollow form produces a communication between said auxiliary chamber and said outlet.

2. A lubricant injector comprising a main bore and an auxiliary bore, coaxial inlet and outlet means connected with the main bore, coaxial spaced annular packing means in the main bore, a coaxial hollow spacer for said packing means, a hollow injector piston movable through said packing and spacing means, said piston being closed at its front end directed toward vthe inlet and being open at its rear end directed toward the outlet. said open rear end of the piston being in communication with an intermediate lat-- eral recess in the piston, means, which in the absence of a predetermined pressure in the inlet biases the piston toward an initial Vposition wherein the said recess is within said hollow spacer,

said second bore being in communication with the hollow spacer and through the piston to said outlet when the piston is in its initial position, a metering piston movable in said second bore. means biasing said metering piston toward an initial position wherein the auxiliary chamber discharges toward the outlet through the spacer and the metering piston, the face of said injector piston being arranged so that under pressure from the inlet communication 'is eilected between the inlet and said auxiliary chamber when said injector piston is displaced from its initial position, displacement of said injector piston being adapted to squeeze to said outlet part of a charge moved therethrough from the auxiliary chamber.

3. A lubricant injector comprising a main bore and a parallel auxiliary bore, coaxial inlet and outlet means `connected with the main bore, coaxial spaced annular packing means in the main bore, a coaxial hollow spacer for said packing means, a hollow injector piston movable through said packing and spacing means, said piston being closed at its front end directed toward the inlet and being open at its rear end directed toward the outlet, said open rear end of the piston being in communication with an intermediate lateral groove around the piston, means which in the absence of a predetermined pressure in the inlet biases the piston toward an initial position wherein the said groove is within said hollow spacer, said second bore being in communication with the lhollow spacer and through the piston to said outlet when the piston is in its initial position, a metering piston movable in said second bore, means biasing said metering piston toward an initial position wherein the auxiliary chamber discharges toward the outlet through the spacer and the injector piston, adjustable means limiting the displacement of said metering piston against its bias, means limiting-the maximum adjustment, telltale means associated with said metering piston and extending from the adjusting means to indicate its position, the face of said injector piston being; arranged so that under pressure from the inlet communication is effected between the inlet and said auxiliary chamber when said injector piston is displaced from its initial position, displacement of said injector piston being adapted to squeeze to said outlet part of a charge moved therethrough from the auxiliary chamber. Y

4. A lubricant injector comprising abody having therein a main bore, an auxiliary bore, a pressure lubricant inlet in communication with said main bore and a passage connecting said bores, coaxial spaced annular packings in said main bore having a coaxial annular spacer therebetween, said spacer having a radial port in communication with said passage, a. discharge tting secured in said main bore and retaining said packings and spacer therein, said tting having a piston chamber'therein at its end adjacent said packings and a check valve in its other discharge end, a ported injector piston movable in said chamber and in said packngs and spacer, means biasing said injector piston toward an initial position wherein its port establishes communication from said auxiliary bore through said passage and spacer portto said chamber, a metering piston movable in said auxiliary bore, and

means for biasing said metering piston to force lubricant from said auxiliary bore into said chamber when the injector piston is in its initialiposition. said injector piston being movable against its bias by pressure of lubricant in said inlet for discharging lubricant in said chamber through said check valve from said initial position to a position wherein communication is established from said inlet through said spacer and passage to said auxiliary bore.

ALEXANDER P. FOX.

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

Number 10 N umher UNITED STATES PATENTS Name Date Williamson Aug. 9. 1932 Hawks Nov. 7, 1933 Hallerberg Jan. 2, 1934 Klein May 19, 1942 FOREIGN PATENTS Country Date France May 20, 1930 (Addition to No. 590,554) Great Britain May 19, 1927

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