US2795360A - Self-pressurizing lubricating pump - Google Patents

Description

June 11, 1957 G. R. MoR'roN SELF-PRESSURIZING LUBRICATING PUMP 2 Sheets-Sheet 1 Filed April 11, 1955 @B-e R.

June ll, 1957 G. R. MCRTON SELF-PRESSURIZING LUBRICATING PUMP 2 Shets-Sheet 2 Filed April 11, 1955 Y A, :.U//Vf G-ren R. fyon Unite States Patent O SELF-PRESSURIZING LUBRICATING PUMP Glen R. Morton, Omaha, Nebr., assignor of three-fourths to A. Hiram Sturges, Omaha, Nebr.

Application April 11, 1955, Serial No. 500,485

3 Claims. (Cl. 222-261) This invention relates to hand operated grease guns of the type in which the plunger is manually operated Without leverage, straight hand operated plunger guns being handier in certain uses than compound leverage grease guns, one advantage of the former guns being that they can be adapted for use where a single plunging motion is -sullicient whereby the gun can be handled in one hand.

In straight hand operated guns the grease must be passed through a very constricted pathway and because of this such guns have heretofore not worked well in cold weather because the grease cannot flow through this long and constricted pathway when the grease is stift and cold.

The reason the grease passageway is so constricted in this type of gun is because the piston is of a small diameter and long rather than of the large diameter and short, the former being necessary because there is no leverage.

Heretofo-.re the return stroke of the plunger in guns of this type has been used only to prepare for the down pumping stroke. It is an object of this invention to make additional use of the return stroke of the plunger to pump air behind the grease following piston.

Also such guns become air-locked even in summer because air gets into the reservoir when the reservoir is being lled with grease.

It is therefore an object of this invention to provide a grease gun having a sufficient pressure behind the grease following piston to push air through and out of the gun along with the grease.

Other and further objects and advantages of the present invention will be apparent from the following detailed description, drawings and claims, the scope of the invention not being limited to the drawings themselves as the drawings are only for the purpose of illustrating a way in which the principles of this invention can be applied.

Other embodiments of the invention utilizing the same or equivalent principles may be used and structural changes may be made as desired by those skilled in the art without departing from the present invention and the purview of the appended claims.

ln the drawings:

Figure 1 is a top plan view of the present invention.

Figure 2 is a greatly enlarged side View in cross section on line 2-2 of Figure l, showing the components of the present invention at the completion of the lubricant pumping movement and an air pumping movement.

Figure 3 is an end View in cross section on line 3-3 of Figure 2.

Figure 4 is a further end view in cross section on line 4-4 of Figure 2.

Figure 5 is a partial view in cross section showing the components of the present invention at the completion of an air inlet or reverse stroke of the plunger and the associated air piston.

Referring in greater detail to the drawings in which like numerals indicate like parts throughout the several views, the present invention consists of a self-pressurizing grease gun or lubricant pump in which there is an outer cylinder having a nozzle or dispensing outlet 11 in which is a check valve 12 including an O-ring 13, as seen in Figures 2 and 5.

A lloating piston 14 within the cylinder 10 subdivides or separates the cylinder 10 into a lubricant chamber 15 and an air chamber 16, the piston 14 being Ashown in Figure 2 near the limit of its movement into the air chamber 16. Air pressure in the air chamber 16 will move the piston 14 into the lubricant chamber 15, forcing the grease or lubricant contained therein into the port 17 adjacent the one end 18 of an inner cylinder 19 which has its one end 18 threaded on a reduced end portion 20 of the relief valve body 21, the latter receiving in its other end the one end of the nozzle or dispensing outlet 11.

The inner cylinder 19 is arranged concentrically with respect to the outer cylinder 10 and has within it a concentrically arranged grease ejection or pump tube 22 connected in communication at one end with the bore of theY relief valve body 21.

The other end of the tube 22 is anchored in a cup washer 23 seated on a resilient gasket 24 positioned within a recess in the adjacent end of a partition plug 25, the latter dividing the cylinder 19 into a lubricant pumping chamber 26 and an air pumping chamber 27.

A plunger 28 reciprocates in the tube 22 to force the lubricant through the outlet 11, the lubricant entering the tube 22 by Way of the port 17 inthe inner cylinder 19 and by way of another port 29 in the tube 22 adjacent the end of the latter where it is connected to the plug 2S.

The other end 30 of the inner cylinder 19 is threadefdly connected to the end cap 31 through which slides a plunger extension member 32 of tubular construction sealed by the washer 33 in the end cap 31. The one end 34 of the extension member 32 is seen in Figures 2 and 5 to be threadedly connected to a piston plug 35 which slides within a piston 36, the latter operating in the inner cylinder 19 and having an O-ring 37 sealing it for sliding movement therein.

The piston 36 is retained upon the piston plug 35 by the enlarged end 38 of the plug 35 which forms a valve seat for another O-ring 39, the latter closing the passage between the plug 35 and the piston 36 upon outward or intake stroke of the extension member 32, the air behind the piston being forced to ow, as indicated by the arrows in Figure 5, around the end and sides of the extension member 32 past the ball check Valve 39' and into the airchamber 16 behind the piston 14.

During this intake stroke, the air ows as shown by the arrows in Figure 5 from the passage 40 in the extension member 32 between the reduced end 41 of the plunger 28 and the inner wall of the bore 42 in the piston plug 35.l

From there it flows into the air pumping chamber 27, ready for the next stroke which will pump air into the air chamber 16.

The reduced end 41 of the plunger extension member 32 has out-struck shoulders 43, one on each side, which engage the end of the plug 35 on the intake stroke, pulling the plunger 28 in its tube 22 so that a new charge of lubricant enters the tube 22. On the lubricant pumping movement of the plunger 28 and the extension member 32, the face of the piston plug 35 seats on the check valve Washer 44, as seen in Figure 5, closing communication between the passage 40 and the air pump chamber 27.

A handle 45 is secured to the one end of the extension member 32 exteriorly of the cylinder 10 and is provided with a passage 46 connected in communication with the passage 40. An air filter 47 in the handle 45 filters the air being admitted to the air chamber 16 through the passage 46 and the passage 40 so that no `dirt or grit is permitted behind the piston 14.

When all of the lubricant contained in the lubricant chamber 15 has been used, more lubricant may be ad- Pfented .lune 11, 1957` mitted to the lubricant chamber by means of the` conventional plug 48 having a conventional check valve mechanism therein not here illustrated as being a part of the invention. To let the air out of the chamber 16, the knurled screw 49 having a tiat on one of its sides is loosened, permitting the air to escape as the new charge of lubricant fills the lubricant chamber 15 and moves the piston 14 toward the handle.

Another end cap 50 closes the other end of the cylinder 10 and a nut 51 tightens the assembly of the inner and outer cylinders on the valve body 21.

In usethe reciprocatory pumping `movement ofthe` plunger 28 as it pumps lubricant to the dispensing outlet` will cause air pumping movements ,of the Vpiston plug and its associated piston 36 to cause an increase in pres,- sure in the air chamber 16. When the lubricant chamber 15 is lled with heavy lubricant, the resistance to flow is the greatest and the air pressure in the air chamber 16 will build up quickly to force the piston ahead to move the lubricant into the tube 22. The air pressure within the air chamber 16 will be reduced as the lubricant is pumped from the dispensing outlet.

From the foregoing description, it is thought to be obvious that a self-pressurizing lubricating pump constructed in accordance with my invention is particularly well adapted for use by Ireason of the convenience and facility with which it may be assembled and operated, and vit will also be obvious that my invention is susceptible of some change and modification ywithout departing from the principles and spirit thereof, and for this reason I do not wish to be understood `as limiting myself to the precise arrangement and formation ofthe several parts herein shown in carrying out my invention in practice, except as claimed.

I claim:

1. A lubricating pump comprising a closed cylinder having a dispensingoutlet at one end, another cylinder arranged concentrically within said rst-named cylinder and having its ends connected to the adjacent ends of said first-named cylinder, a piston surrounding and slidably supported on said second-named cylinder, said ,piston subdividing the space between said cylinders into a lubricant chamber and an air chamber, a lubricant pump element mounted in said second-named cylinder `.for movement toward and away from said dispensing outlet, said lubricant chamber being in communication with said secondnamed cylinder adjacent said dispensing outlet and `said air chamber being in communication with said secondnamed cylinder remote from said dispensing outlet, and air pump means within said second-,named `cylinder and operatively connected to saidlubricant pump element for effecting the movement of said pump element toward and away from said dispensing outlet.

2. A lubricating pump comprising a closedcylinder having a dispensing outlet at one end, another cylinder arranged concentrically within said ltirst-named `cylinder and having its ends connected to the adjacent ends of said rst-named cylinder, a piston surrounding and slidably supported on said second-named cylinder, said piston subdividing the space between said cylinders into a lubricant chamber and an air chamber, means in said second-named cylinder subdividing the space therein into a lubricant pump chamber adjacent said dispensing outlet and an air pump chamber remote from said dispensing element, said lubricant chamber being in communication with said lubricant pump chamber `and said air chamber being in communication with said air pump chamber, a lubricant pump element mounted in said lubricant pump chamber for movement toward and away from said dispensing outlet, an air piston mounted within said `air `pump chamber vfor movement toward and away rom said dispensing outlet and operatively connected to said lubricant pump element for effecting the movement of said pump element toward `and away .from said dispensing outlet, and operating means projecting by one end from the other end of said first-named -cylinder having its other `end operatively connected to said air piston for effecting the movement of said air piston toward and away from said dispensing outlet.

3. A lubricating pump comprising a closed cylinder having azdispensing outlet at one end, another cylinder arranged concentrically within said tirst-named cylinder and having its ends connected to the adjacent ends of said rstnamed cylinder, a piston surrounding and slidably supported on said second-named cylinder, said piston subdividing the space between said cylinders into a lubricant chamber and an air chambenvmeans in said second-named cylinder subdividing the space therein into a lubricant pump chamber adjacent said `dispensing outlet, said lubricant chamber being in communication with said lubricant pump chamber and Said air chamber being in communication with said air pump chamber, a lubricant pump element mounted in said lubricant pump chamber for movement toward and away from said dispensing outlet, an air piston mounted within said air pump cylinder for reciprocal movement toward and away `from said dispensing outlet and operatively connected to said lubricant pump element for effecting the movement of said pump element toward and away from said dispensing outlet, and handle means exteriorly of said first-named cylinder having an end portion projecting thereinto operatively connected to said `air piston for effecting movement of the latter, said handle means being provided with a passagefor air communicating with said air pump chamber.

References Cited in the tile of this patent UNITED STATES PATENTS

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