US2872085A - Lubricating apparatus - Google Patents

Description

Feb. 3, 1959 c. H. MUELLER 2,872,085

LUBRICATING APPARATUS Filed Dec. 21, 1956 isgiiigxunmuuk United States LUBRICATING APPARATUS Carl H. Mueller, Pasadena Hills,

McNeil Machine & Engineering Company, Akron, Ohio, a corporation of Ohio Application December 21, 1956, Serial No. 629,928 3 Claims. (Cl. 222-376) Mo., assignor Vto The atent gce biased toward this seat by a spring 39 reacting om the stroke operation, and the provision of such a grease gun which is economical to manufacture and reliable in operation for various grades of grease. Other objects and features will be n part apparent and in part pointed out hereinafter.

The invention accordingly comprises the constructions hereinafter described, the scope of the invention being indicated in the following claims.

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

Fig. l is a view partly in side elevation and partly in longitudinal cross section of a grease gun of this invention;

Fig. 2 is an enlarged section taken on line 2 2 of Fig. l; and,

Fig. 3 is an enlarged fragment of Fig. l illustrating a moved position of parts.

Corresponding reference characters indicate corresponding parts throughout the several views of the Idrawings.

Referring to the drawings, a grease gun of this invention is Ishown to comprise a container or barrel 1 for containing a supply of grease. At one end of the barrel 1 is a pump generally designated P. This pump comprises a head 3 screwed on the end of the barrel and having a bore 5 extending transversely with respect to the barrel. This bore constitutes the pump cylinder. A pump plunger 7 reciprocates in the bore or cylinder 5. The plunger extends out of one end of the cylinder 5 (the rearward end `of the cylinder). A hand lever 9 is pin-connected at 11 adjacent one end to the end of the plunger which extends out of the cylinder. A link 13 is pin-connected at 15 to this end of the lever and pinconnected at 17 to the head 3. The arrangement is such that by swinging the lever away from the barrel 1, the plunger 7 is pulled out through ia 'priming or return stroke, and by swinging the lever toward the barrel, the plunger is pushed in through a pressure stroke.

The head 3 is formed with a main lateral inlet port 19 for the cylinder 5 through which grease may ow from the barrel 1 into the cylinder 5 when the plunger 7 is fully retracted through a full return stroke. In the 'barrel is a follower 2l biased toward the head 3 by a spring 23 for forcing grease from the barrel into the cylinder. The forward end of the cylinder 5 is closed by a plug 25. The head is formed with a lateral outlet port 27 adjacent the forward end of the cylinder. Screwed in the outlet port 27 is an outlet pipe 29. On the outer end of the pipe is a conventional hydraulic coupler 31.

The forward end portion of the cylinder 5 is enlarged as indicated at 33 to provide a forwardly facing valve seat 35 inward of the outlet port 27. A valve ball 37 is plug 25. The head P is formed with ,an yauxiliary lateral inlet port 41 for the cylinder 5 inward of and closely adjacent the valve seat 35 through which grease may iiow'` from the barrel 1 into the cylinder 5 when the plunger 7 is retracted through a short stroke.y The auxiliary port 41, as shown best in Fig. 2, is drilled .at an angle intersecting the cylinder 5 at one side. The port 41 is counterbored to form an outwardly' facing valve seat 43 located between the barrel end of the port and the cylinder 5. A valve ball 45 is inserted in the port 4l from its outer end for engagement with the seat 43 under pressure from the cylinder 5 to block olf flow of grease from the cylinder back into the barrel through port 41. A conventional iller nipple 47 is threaded in the outer end of port 4l and closes it. A spring 49 is interposed between the inner end of the nipple 47 yand a shoulder 51 formed in the port 41.

Operation is as follows:

0n a full return stroke of the'plunger 7, the plunger is withdrawn to the left as viewed in Figs.A 1 and 3 beyond the main inlet port 19v for priming of the cylinder 5 with grease from the barrel l.. Some grease may enter the cylinder via the ball-checked :auxiliary inlet port 41, but priming occurs mainly via the wide-open main inlet port 19 to insure full and rapid priming, even in the case of heavy grease. Then, on a pressure stroke of the plunger, the inlet port 41 is closed by the valve ball 45 to prevent return of grease to the barrel via port 41, valve ball 37 opens, and the charge of grease in the cylinder is delivered through the outlet port 27.

In the case the gun need-s to be used in confined quarters where it is not possible to take a full stroke of the lever 9 and the plunger 7,-a short return stroke of the plunger to the point where port 41 is open to the cylinder 5 (see Fig. 3) will prime the cylinder via port 41. Then, on a pressure stroke of the plunger, the ball 45 closes and the charge of grease (in this case asmall charge) is delivered through the outlet port 27.

In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained. a

As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying. drawings shall be interpreted as illustrative and not in a limiting sense.

I claim:

' l. Lubricating apparatus comprising a lubricant container and a pump, the pump comprising a body having a bore therein constituting `a pump cylinder and a plunger slidable in the bore, said 'body having a main inlet intersecting the bore ladjacent one end of the bore which constitutes the rearward end of the bore and an auxiliary inlet intersecting the bore between the main inlet and the other and forward end of the bore for ow of lubricant from the container to the bore, said plunger being slidable in the bore between a fully retracted position wherein the forward end of the plunger is rearward of at least part of the main inlet and a forward position wherein its forward end is forward of the auxiliary inlet, said body having an outlet in communication with the forward end of the bore, a check valve in the outlet adapted to open in response to lubricant pressure developedon a forward stroke of the plunger and to close on a return stroke of the plunger, a valve seat in the auxiliary inlet facing in'the direction of flow toward the bore, and an auxiliary check Valve in the auxiliary inlet engageable with said valve seat, said auxiliary check valve being constantly free to move away from said valve seat to open on a return stroke of the plunger and adaptedin response to lubricant pressure developed in the bore on a Patented Feb. a,` A1959V forward stroke of the plunger to seal against said valve seat and block off ow from the bore back to the contain er through'the auxiliary inlet, whereby the plunger'is adapted either for full-stroke operation or for short-stroke operation involving retraction thereof from its forward positionI to an intermediate position wherein its forward end is rearward of at least part of the auxiliary inlet and yforward of the main inlet.

2. A grease gun comprising a barrel for containing grease, a head at one end of the barrel having a bore therein constituting a pump cylinder, la plunger slidable in the bore, a lever carried by the head for moving the plunger, the head having a main inlet intersecting the bore adjacent one end of the bore which constitutes the rearward end of the bore ,and an auxiliary inlet intersecting the bore between the vmain inlet and the other and forward end of the bore for ow of grease from the barrel to the bore, said plunger being slidable inthe bore between a fully retracted position wherein the forward end of the plunger is rearward of at least part of the main inlet and a forward position wherein its forward end is forward of the auxiliary inlet, said `head having an outlet at the forward end of the bore including a portion of larger cross section than the bore and being formed so that there is a forwardly facing annular valve seat lsurrounding the forward end of the bore, a spring-biased outlet check valve engageable with said forwardly facing valve seat adapted to open in response to grease pressure developed 4 in the bore on la forward stroke of the plunger, a valve seat in the .auxiliary inlet facing in the direction of ow toward the bore, and a check valve 'in the auxiliary inlet engageable with said valve seat in the auxiliary inlet, said check valve for the auxiliary inlet being constantly free to move away from the valve seat in the auxiliary inlet to open on a return stroke of the plunger and adapted in response to grease pressure developed in the bore on a `forward stroke of the plunger to seal against said auxiliary inlet vaive seat and block off flow from the bore 'back to the barrel through the auxiliary inlet, whereby the plunger is adapted either for full-stroke operation or for shortstroke operation involving retraction thereof from its forward position to an intermediate position wherein its forward end is rearward of at least part of the auxiliary inlet and forward of the main inlet.

3. A grease gun as set forth in claim 2 wherein the auxiliary inlet is constituted by a passage extending completely through the head and intersecting the bore, said 'passage being formed adjacent its end toward the barrel with said auxiliary inlet valve seat, the outer end of the passage being closed by a filler nipple.

l2,012,923 Bystricky Aug. 27, 1935

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