US3038768A

US3038768A - Lubricant-gun follower packing

Info

Publication number: US3038768A
Application number: US838673A
Authority: US
Inventors: Kludt Jonathan
Original assignee: McNeil Machine and Engineering Co
Current assignee: McNeil Machine and Engineering Co
Priority date: 1959-09-08
Filing date: 1959-09-08
Publication date: 1962-06-12
Anticipated expiration: 1979-06-12

Description

United States Patent 3,038,768 LUBRICANT-GUN FOLLOWER PACKING Jonathan Kludt, St. Louis, Mo., assignor to The McNeil Machine & Engineering Company, Akron, Ohio, a corporation of Ohio Filed Sept. 8, 1959, Ser. No. 838,673 4 Claims. (Cl. 277-212) This invention relates to a packing unit for lubricant guns, and more particularly to unitary packing for followers of grease guns of the type having a barrel for containing a supply of grease, a pump at one end of the barrel, and a follower slidable in the barrel for forcing grease toward the pump.

In the coassigned Klein et a1. United States Patent 2,886,215 dated May 12, 1959, entitled, Lubricant Gun, there is shown a special follower made of rubber or the like for a grease gun of the class above described which, in one position, is adapted for easy entry into a grease cartridge such as may be inserted in the barrel of the gun and for sliding sealing engagement in the cartridge, and which, in a flipped-over position, is adapted to enable the gun to be used as a bulk grease gun (in which case there is no cartridge in the barrel and the barrel is loaded by means of a filler pump or suction).

Among the several objects of this invention may be noted the provision of a special follower packing for a grease gun of the class described which, without any necessity for flipping it over, adapts the gun for use either as a cartridge-type gun or as a bulk grease gun, the follower being adapted for easy entry into a cartridge and to make a tight seal against the cartridge to prevent by-passing of grease around the follower and, without flipping over the packing, to make a tight seal against the barrel when the gun is used as a bulk grease gun; and the provision of follower packing having the stated features which is economical to manufacture and reliable in use. Other objects and features will be in 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. 1 is a longitudinal section of a grease gun, illustrating a cartridge in the barrel of the gun, and illustrating the follower of the gun in an intermediate position in the cartridge;

FIG. 2 is an enlarged section taken on line 2-2 of FIG. 1, illustrating the follower near the pump of the s FIG. 3 is a view similar to FIG. 2, without a cartridge in the barrel, showing the follower as it appears when the gun is used as a bulk grease gun;

FIG. 4 is a section of the packing mem ber per se as it appears when disassembled from the gun and uncompressed; and,

FIG. 5 is a section taken on line 5-5 of FIG. 1.

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

Referring to the drawings, a grease gun is shown to comprise a container or barrel 1 for containing a supply of grease. The barrel may consist, for example, of a metal tube. At one end of the barrel 1 (this end constituting the forward end of the barrel) is a pump generally designated P. The pump comprises a head 3 screwed on the forward 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 3,fl38,758 Patented June 12, 1962 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 pin-connected 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 a 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 lateral inlet port 19 for the cylinder 5 through which grease may flow 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 21 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 biased toward this seat by a spring 39 reacting from the plug 25. The head 3 is provided with a conventional filler nipple 41 (see FIG. 2) for filling of the barrel 1 with bulk grease by means of a conventional filler pump.

In accordance with this invention, the follower 21 is of special construction, comprising a hub generally designated 45 carrying a special resilient packing member or device 47 which may be made of a suitable flexible greaseresistant synthetic rubber or the like. The packing member 47 (shown normally in FIG. 4 as manufactured) is formed as a cup having a central cylindrical sleeve 49 at a head end (its forward end toward the forward end of the barrel 1). The head end is formed as an integral outwardly extending circular flange 511 having a flat bottom (forward) face 53 and a. conical top (rearward) face 55. Flange 51 is thus of annular conical form, its thickness diminishing from sleeve 49 out to its periphery. Extending back from the periphery of the flange 51 is a barrel-shaped annular wall portion 57. This surrounds the sleeve 49, being spaced radially outward from the sleeve.

In its unstressed, normal or unconfined condition, annular wall portion 57 of packing member 47 is of rounded bulbous or barrel form, convex as regarded from the outside, concave as regarded from the inside (see FIG. 4). It extends back beyond the rearward end of the sleeve 49, where it has a thickened internal annular head or shoulder 59 formed with an internal cylindrical surface 61 coaxial with the sleeve 49. Extending rearward from the outer margin of the bead '57 is an annular conical lip 63 which flares outward from the bead, the outer edge of the lip at its rearward end (which is its larger end) having approximately the same diameter as the maximum diameter of the bulbous annular wall portion 57 when the packing member is in its unstressed, normal or unconfined condition. Lip 63 is thin relative to the bead 59. The packing member 47 is formed with an annular grooove 64 surrounding the flange 51 on the rearward side of the flange at the juncture of the flange with the bulbous annular Wall portion 57, so that the annular wall portion 57 is relatively thin at its juncture with the flange 51. From this region, the annular wall portion gradually increases in thickness back to the head 59.

The hub 45 comprises a tubular metal bushing 65 provided with forward and

rearward end heads

57 and 69. The forward end head 67 is constituted by a flat circular metal washer surrounding the bushing and engaging an enlarged forward end portion 71 of the bushing. The

sleeve 49 of packing member 21 has a tight sealing fit on the bushing 65, the flat forward face 53 of flange 51 of packing member 21 engaging the forward end head 67. The rearward end head 69 is constituted by a cup-shaped sheet metal member having a central opening receiving a reduced-diameter portion of bushing 65 at the rearward end of the latter, and is held in place on the bushing by peening as indicated at 73. Rearward end head 69 engages the rearward end of the sleeve 49 of packing member 21. It has a rearwardly directed cylindrical wall 75 coaxial with the bushing 65 and the sleeve 49 of packing member 21. The outside diameter of wall 75 corresponds to the diameter of the internal cylindrical surface 61 of the bead 57 of packing member 21, the bead thereby having a sliding sealing fit on surface 61. Wall 75 has a rearward outwardly directed flange 77 overlying the bead and on the inside of lip 63, flange 77 being spaced from the rearward end of the bead. The bushing 65 has an axial bore 79 with a counterbore 81 at its rearward end receiving packing 83. This packing is compressed in the counterbore 81 by a washer 85 held in place by peening a portion of the bushing as indicated at 87.

At 89 is indicated a follower rod which extends through the bushing 65. Bushing packing 83 has a sliding sealing fit on the rod. The barrel 1 has a cap 91 threaded on its rearward end (see FIG. 1). The follower rod has a length somewhat greater than that of the barrel and extends slidably through a central opening 93 in the cap. The outer end of the rod 87 is formed as a handle as indicated at 95. The opening 93 may be circular with a lateral notch as in the gun shown in US. Patent 2,394,488, and the rod 89 may have a groove 97 as in said patent for locking the rod in a retracted pulled-out position by angling the rod to bring the groove into the lateral notch. At the inner end of the follower rod 89 is a cross-pin 99. Secured to the forward end head 67 of hub 45 as by spotwelding is a U-shaped sheet metal member 101 having a slot 163 of the elongate centrally enlarged shape shown in FIG. 5. The rod 89 may be turned to align pin 99 with slot 103 or to disalign it from this slot.

As previously stated, the annular wall portion 57 of the flexible resilient packing member 47 is of bulbous form in its unconfined uncompressed condition out of the barrel of the gun. its maximum diameter is then somewhat greater than the internal diameter of the barrel 1 of the gun. For example, in the case of a barrel having an internal diameter of two and one-eighth inches (2.125) the maximum diameter of annular wall portion would be within the limits of 2.155" and 2.170. The diameter of the outer periphery of the lip 63 at its rearward (large) end is the same, i.e., 2.155-2.170. The forward end head 67 on bushing 65 is of smaller diameter than the internal diameter of a cartridge to be loaded in the barrel 1.

FIGS. 1 and 2 show the gun in use as a cartridge gun, i.e., loaded with a cartridge of grease comprising a tube T which is fill-ed with grease and which, as supplied, has closure caps (not shown) at its ends. The tube T has a large opening at one end and a small opening at the other. To load a cartridge in the gun, the pump P is removed from the barrel 1. The follower rod 89 is pulled out and locked in pulled-out position by angling it for engagement of groove 97 in the lateral notch of the opening 93 in the barrel cap 91. This pulls the follower 21 back to the rearward end of the barrel and holds it there against the bias of spring 23. The caps having been removed from the tube T, the tube T is inserted into the barrel 1 (from the forward or pump end of the barrel) with the end of the tube T having the large opening being inserted first.

The pump P is then replaced on the barrel 1, and the follower rod 89 unlocked from the barrel cap 91. Holding the follower rod 89 back so that the pin 99 is located between plate 101 and the forward end of bushing 65, the follower rod is turned to disalign pin 99 and slot 103. Then the follower rod 89 is pushed in. This pushes in the follower 21. As the follower is pushed in, the bulbous annular wall portion 57 of the packing member 47 of the follower is readily radially compressed to generally cylindrical form as it enters the end of the tube T so that it easily enters the tube and comes into sliding sealing engagement with the interior surface of the tube to force the grease in the tube toward the pump P without leakage of grease past the packing member. As the annular wall portion 57 is compressed on entering the tube T, its rearward end slides rearward on cylindrical wall 75 of the rearward end head 69, the latter serving to keep the annular wall portion 57 from collapsing thereby to prevent the pressure of the grease from breaking the seal between the annular wall portion 57 and the tube T. The lip 63 is also compressed to generally cylindrical form. Pressure is applied by hand to the follower rod 89 to expel any air that may have been trapped by the ball check valve 37, and then the follower rod is disengaged from the follower 21 by aligning the pin 99 and slot 193 and pushing the rod into the FIG. 1 position. Then the gun is ready for use.

If the gun is to be loaded with bulk grease instead of a cartridge, no change in the follower 21 is needed. The annular wall portion 57 of the packing member 47 is then radially compressed substantially to cylindrical form in the barrel (see FIG. 3), not so much as when in a cartridge tube T, but still sufficient for sliding sealing engagement with the internal surface of the barrel. The gun may be loaded with bulk grease either by utilizing a filler pump to pump grease into the barrel 1 via filler nipple 41, or by removing the pump P, inserting the open end of the barrel in a container of grease, and sucking grease into the barrel by pulling back the follower 21. In the latter case, lip 63 is particularly effective to insure against such leakage of air around the follower as would break the suction, being pressed outward into tight engagement with the barrel by the air pressure built up in the barrel rearward of the follower on pulling the follower back.

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

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:

1. A follower packing unit composed throughout of resilient material and for use in the supply barrel of a lubricant gun operable with or without lubricant cartridges, comprising a cup formed of a flexible annular wall which normally is of bulged barrel shape, said cup having an open end formed by an outwardly flaring lip shaped for marginal flexibility and connected with the annular wall by an inwardly directed supporting shoulder shaped to have less marginal flexibility than that of said wall or said lip, a central sleeve, the other end of the barrel-shaped wall being connected with said sleeve by a supporting flange which is shaped also to have less flexibility than that of said wall or said lip, the marginal portions of said flange forming a connection with the well, said sleeve, flange and shoulder being adapted to form connections for the packing with central follower parts in the barrel of the gun, said annular wall being adapted to change from its normal barrel shape to a substantially cylindrical shape extending between the flange and the shoulder upon insertion into cylinders of different diameters to effect an elongate seal therebetween, said flaring lip adapted to form an adjacent seal with said cylinders.

2. A follower packing unit according to claim 1, where- 5 in opposite faces of the marginal portions of said flange converge where the flange connects with the wall.

3. A follower packing unit according to claim 1, wherein the connection between the flange and the wall is grooved to facilitate said change of the annular wall from its barrel shape to its cylindrical shape.

4. A follower packing unit according to claim 2, wherein the connection between the flange and the wall is grooved to facilitate said change of the annular wall from its barrel shape to its cylindrical shape.

References @iteri in the file of this patent UNITED STATES PATENTS Gosling Feb. 1, 1944 Dick July 22, 1947 Vielmo Jan 15, 1957 Klein et al. May 12, 1959 Peras June 2, 1959