US3059819A

US3059819A - Optional loading grease gun

Info

Publication number: US3059819A
Application number: US785689A
Authority: US
Inventors: Edwin P Sundhohn
Original assignee: Individual
Current assignee: Individual
Priority date: 1959-01-08
Filing date: 1959-01-08
Publication date: 1962-10-23
Anticipated expiration: 1979-10-23
Also published as: GB917718A

Description

1962 E. P. SUNDHOLM 3,059,819

OPTIONAL LOADING GREASE GUN Filed Jan. 8, 1959 2 Sheets-Sheet 1 i), i W 32 as 25 'll/II III IX r/ uucr Juu" IN WIN TOR:

I 40 39145 47 4 O 42 Bram; 4411, 4444 mi w 3, 1962 E. P. SUNDHOLM OPTIONAL LOADING GREASE GUN 2 Sheets-Sheet 2 Filed Jan. 8, 1959 ATTORNEYS.

United States Patent Office 3,059,819 Patented Get. 23, 1952 3,959,819 @PTIONAL LGADING GREASE GUN Edwin P. Sundhohn, Albert City, Iowa Filed Jan. 8, 1959, der. No. 785,689 3 Claims. (ill. 222-326) This invention relates to an optional loading grease gun, that is, a grease gun which is adapted for use selectively with both cartridge-packaged greases and bulk-filled greases, including both the pressure and suction filling of bulk greases.

The use of cartridge-packaged greases in connection with grease guns has increased rapidly in recent years, and guns have been provided for utilizing the grease in the cartridge-packaged form. Such grease guns, however, have suffered from the disadvantage that they could not also be used with bulk greases. An effort has therefore been made to provide an optional loading grease gun which is adapted for use with both cartridge-packaged greases and bulk-filled greases. Heretofore, this effort has only been partially successful, and the problems presented have not been completely solved.

The problem discussed above is rendered particularly difiicult because of the fact that bulk greases are commonly introduced into grease guns in a variety of ways. The grease may be loaded by pumping it into the barrel of the grease gun, or the grease may be sucked into the barrel. In One procedure in common use, the dispensing head is removed from the grease gun and the forward end of the barrel is inserted in an open pail of grease. The plunger is then slowly withdrawn within the barrel to suck the grease into the gun. In another procedure, the grease is sucked into the barrel through an opening in the dispensing head from a special container which is constructed so that a tight connection can be made between the interior of the grease gun and the interior of the container. In connection with the pressure filling method, it is common to use gun-filling pumps which deliver the grease under pressure, the grease being introduced through a valve-controlled opening in the dispensing head. Obviously, therefore it is a difficult problem to provide a grease gun which is adapted for use with cartridge-packaged greases and which can also be loaded by any of the pressure-filling or suction-filling procedures just described.

Even if the gun was to be designed only for the use of bulk-filled greases, the problem is a difficult one where it is desired to be able to load the gun by both pressure and suction methods. When the plunger of the grease gun is designed so as to create sufiicient suction on the backstroke for drawing grease into the gun, it tends to perate less effectively in the dispensing operation. If the piston is backed with a spring for urging the piston towards the dispensing head, as is usually desirable, this may tend to cause the suction-type plunger to move inwardly without keeping all of the grease ahead of it. A similar problem is encountered when it is attempted to fill such grease guns by pumping grease into them. The grease which is introduced under pressure tends to force its way past the piston, particularly if the piston is backed with a string, and the presence of grease in the portions of the gun behind the piston can create unpleasant difiiculties for the operators of the guns.

It is therefore an object of the present invention to provide a grease gun which substantially overcomes the problems discussed above. A more specific object is to provide a grease gun which not only can be filled by any of the suction or pressure methods in common use, but which is also adapted for use with cartridge-packaged greases. Further objects and advantages will appear as the specification proceeds.

An illustrative embodiment of the present invention is shown in the accompanying drawings, in which- FIGURE 1 is a side sectional view of a grease gun embodying the present invention;

FIGURE 2 is an enlarged fragmentary side sectional view showing the rear end portion of the grease gun cylinder or barrel of FIGURE 1;

FIGURE 3, an enlarged detail fragmentary side elevational view illustrating the relationship of the plunger to the grease gun barrel or cylinder when the gun is being used with bulk-filled greases;

FIGURE 4, a sectional plan view taken on line 4-4 of FIGURE 3 and showing the rear side of the plunger;

FIGURE 5, an enlarged sectional view of the plunger taken on line 55 of FIGURE 4;

FIGURE 6 an enlarged fragmentary side sectional view of the grease gun of FIGURE 1 showing the rearward portion of the grease gun with the plunger fully withdrawn and locked in the withdrawn position;

FIGURE 7, a transverse sectional view showing the rear end of the closure cap and taken on line 77 of FIGURE 6;

FIGURE 8 another transverse sectional view taken on line 88 of FIGURE 6 showing the relationship of the parts when the plunger is fully withdrawn;

FIGURE 9 a view showing the forward face of the plunger taken on line 9-9 of FIGURE 6; and

FIGURE 10 a fragmentary enlarged side sectional view of the grease gun of FIGURE 1 showing the forward end portion of the grease gun, the section being taken on a plane turned degrees with respect to the plane of the section of FIGURE 1.

Referring now more specifically to the embodiment shown in the drawings, it can be seen that the grease gun includes a cylindrical grease container 10, a closure cap 11 threadedly connected to the rear of the container, and a grease dispensing head 12 removably mounted on the front end of the container. Within container 10 is a slidable plunger assembly 13 which is designed, as will subsequently be explained in greater detail, to create suction within container 10 when withdrawn or to urge grease towards dispensing head 12 when used with either bulkfilled greases or cartridge-packaged greases. As shown in FIG. 1, a grease cartridge 14 is positioned within cylinder 10, the cartridge being partially filled with grease 15. Behind plunger assembly 13 is provided a compound spring 16, the construction of which will also be further discussed in detail. A plunger rod 17 is provided for the manual actuation of plunger assembly 13, the rod being releasably engageable with the plunger assembly for retractin g, and rotating the assembly.

In accordance with the present invention, the plunger assembly 13 provides an annular portion 18 which is adapted for sealing selectively with the inner wall of a grease cartridge 14 positioned within container 10 or with the inner wall of the container 10. It will be noted that the plunger portion 18 provides a pair of annular blades 18a and 18b one of which extends outwardly and rearwardly and the other of which extends outwardly and forwardly, as shown more clearly in FIGURE 5. The plunger portion 18, which provides the blades 18a and 1812, should be formed of a resilient, flexible material such as a synthetic rubber. It Will be understood that the material should be resistant to deterioration on prolonged contact with grease. In the illustration given, plunger portion 18 is integrally connected to a transversely-extending base portion 19 which provides a central rearwardly-extending hub portion 20 that is slidably received on plunger rod 17, while maintaining a sealing engagement therewith. With the construction shown, the annular portion 18 and the integral base portion 19 can be conveniently formed by a molding operation. In the illustration given, the base portion 19 is locked between

clamping washers

21 and 22. The

washers

21 and 22 provide a plurality of complementary depressions 21a and 22a which extend through openings in the transverse base portion 19 and bear against each other. These projections may be united by spot welding as indicated in FIGURE 6. The rear washer 21 also provides projections 2112, as shown more clearly in FIGS. and 8, which interlock with projections on base portion 19. The outer edge portions 210 and 220 of the washers are turned toward each other to provide a further interlock.

The lower end of plunger rod 17 is provided with an outwardly extending pin 23. In the operation of the device, pin 23 may be drawn into one of the slots 24 between tabs 22b by means of the handle 25 on the rear end of plunger rod 17. The plunger assembly can then be rotated or retracted as desired.

The sleeve 26 encircles plunger rod 17, and has its forward end abutting rear washer 21 around hub 28. As indicated more clearly in FIGURE 8, the forward end of sleeve 26 is provided with a plurality of outwardly extending attachment tabs 27 which are spot Welded to rear washer 22. The intermediate portion of sleeve 25 is provided with integral inwardly-extending tabs 28 and 29, as seen more clearly in FIGURES 6 and 8, which cooperate to provide complementary bearing surfaces around plunger rod 17, thereby assisting in maintaining plunger assembly 13 at right angles to plunger 17 regardless of the position of the plunger assembly or the plunger rod within the grease gun. The rear end of sleeve 25 provides a pair of

arcuate cars

30 and 31. The rear wall of end cap 11 provides a pair of

arcuate slots

32 and 33 which are alignable with

ears

30 and 31 and are arranged to cooperate therewith. The ears are undercut as indicated at 34 (FIGURE 6) for interlocking with raised areas 35 which lie adjacent the ends of

slots

32 and 33. Plunger assembly 13 may be drawn rearwardly until the

ears

30 and 31 extend respectively through

slots

32 and 33, and then the plunger assembly can be slightly rotated so that the ears rest on raised areas 35 thereby releasably locking the plunger assembly in the withdrawn position. The plunger can be released by forceably rotating the ears 3%] and 31 in the opposite direction to bring them into alignment with the

slots

32 and 33.

In accordance with the present invention, container 18 toward the rear thereof is formed inwardly to provide means for contracting the blades 18a and 18b of plunger annular portion 18. Preferably, the inwardly formed portion of container also provides means for holding the upper end of a grease cartridge in centered relation within the container. As shown in FIGURES 1, 2 and 6, an inwardly-extending annular wall portion 37 is provided toward the rear of container 10. Annular wall portion 37 is arranged to depress blades 18a and 18b inwardly to reduce the diameter of the plunger assembly for insertion into the open end of a grease cartridge. More specifically, plunger assembly 13 can be drawn into and through annular container portion 37, thereby reducing the diameter of the contractable plunger portion by depressing blades 18a and 18b inwardly. FIGURE 6 shows the position of the plunger assembly when fully withdrawn and ready for insertion into the open end of a grease cartridge. The cartridge is not shown in FIGURE 6, but it would occupy the position indicated in FIGURE 1.

The particular shape of inwardly extending portion 37 as shown in the drawings has a number of advantages. However, other shapes can be used while still obtaining certain of the benefits of the present invention. As shown more clearly in FIGURES 2 and 6, container portion 37 is composed of a forward section 37:11 which provides an inwardly converging wall, an intermediate section 37b which provides a wall concentric with the body of container 10 but spaced inwardly therefrom, and a rearward section 370 which provides a forwardly converging wall. At the inner end of the forwardly converging section 370 A. is provided a shoulder or abutment 3741. This configuration can be achieved by a rolling operation wherein a correspondingly shaped mandrel is inserted in the container and rollers are applied to the outside of the container to form the wall portion 37 against the mandrel.

In the operation of the device, the forward section 37a will depress the blades 18a and 181) as the plunger assembly is withdrawn, permitting the blades to ride through the intermediate section 37b and over the shoulder 370! to the position shown in FIGURE 6. With the plunger assembly locked in this position by means previously described, a grease cartridge having an open rear end is inserted within the cylinder 19 through the front end thereof, the dispensing head 12 having been previously removed. When the. grease cartridge is fully inserted it will occupy the position shown in FIGURE 1 with the rearward end of the cartridge received within the section 37 b, which due to its concentricity with the body of cylinder 10 assists in holding the grease cartridge, such as grease cartridge 14, in centered relation within the cylinder 18. It will also be observed that the rear edge of the grease cartridge 14 lies just in front of the shoulder 37d, the shoulder at least partially overhanging the rear edge of the cartridge to prevent the forward blade 1812 from catching on the rear edge of the cartridge as the plunger assembly 13 is inserted into the cartridge. The insertion can then be accomplished by simply releasing the plunger assembly 13 and allowing the spring 16 to move the plunger assembly forwardly. Forwardly converging section 37 0 will depress the blade 18]) so that it will ride over shoulder 37d smoothly and into the open upper end of the grease cartridge, and a similar action will then follow with respect to the rearward blade 18a. The position of the plunger assembly 13 within the grease cartridge is illustrated in FIG- URE l where the cartridge is shown partially filled with grease, as it would appear during the use of the gun when part of the grease has been dispensed.

The construction and operation of dispensing head 12 is described more particularly in my copending application Serial No. 669,115, filed July 1, 1957, now Patent No. 2,923,443. For the purpose of this application it is believed suflicient to note that the dispensing head 12 includes a body 38 having a bore 39 therein for slidably receiving piston plunger 40 that extends outwardly beyond body 38 and is pivotally connected to an operating handle 41. The forward end of operating arm 41 is pivotally connected to a pair of links 42 (FIGURE 10), which in turn are pivotally mounted on body 38, thereby permitting piston 40 to be reciprocated by the corresponding reciprocation of arm 41. The bore 49 communicates with an inlet opening 43 which extends through cap 44 and the adjacent wall of body 38 to provide for communication between bore 39 and the interior of container 10 when the piston rod 40 is withdrawn sufficiently to uncover inlet opening 43. Body 38 also provides an opening 45 communicating with the end of bore 39 towards which piston rod 40 advances. A grease discharge fitting 46 is thrcadedly received within an enlarged outer portion of opening 45 and provides a passage 47 therethrough for the outflow of grease from within bore 39. Fitting 47 provides a spring biased check valve 48 which is arranged to permit outflow only through passage 45. As shown in FIGURE 1, the outer end of fitting 46 is adapted to receive a grease applicator pipe 49. As shown in FIGURE 10, the cap 44, which is threadedly connected to the front end of container 10, also provides an inlet opening 50. In the illustration given, opening 50 is internally threaded to receive a filler fitting 51 and thereby mount the same on the outside of head 12 to provide a passage 52 extending from the outside to the inside of container 10. Preferably, fitting 51 includes a sp'ring biased check valve 53 arranged to permit only inflow through passage 52. It will be noted that the outer portion of fitting 51 which encloses valve 53 is removable from the inner portion, being threadedly connected thereto at 54. With this construction, grease can be pumped into container 10 through fitting 51. When it is desired to suck grease into container 10, this can be done by removing the outer portion of fitting 51 which includes valve 53, and connecting the remaining portion of fitting 51 to the container from which the grease is to be obtained. Alternatively, dispensing head 12 can be removed, and the forward end of container 10 can be applied directly to the grease. In either case, the plunger assembly 13 will be in its forwardmost position within the container 16) at the start of the filling operation, and will be slowly drawn rearwardly to create the suction within the container for drawing in the grease. The plunger assembly may also be in its forwardmost position when grease is being pumped into the container since the grease will force the plunger assembly rearwardly until the container is filled with grease.

It is preferred to provide spring means for urging the plunger assembly toward the forward end of the gun, and the specific spring means illustrated in the drawings has a number of advantages. The use of a compound spring, such as spring 16 permits the entire spring to be withdrawn within the rear cap 11 when the plunger assembly is in its rearwardmost position, as indicated in FIGURE 6, while still providing sufiicient spring action during the last portion of the forward movement of the plunger a sembly.

In the illustration given, the spring means 16 includes two coil spring sections 16a and 1612. Section 1612 is of smaller diameter than section 16a and is arranged to telescope within section 16a. The forward end portion of section 16a and the rearward end portion of section 16b are interconnected in overlapping relationship by means of a sleeve 160 as shown more clearly in FIGURES 6 and 8. The forward end of section 16b bears against rear washer 21 of plunger assembly 13, and the rearward end of section 16a bears against the inside of the rear wall of cap 11. The projections 21b of rear washer 21 assist in centering the forward end of spring section 16b.

While in the foregoing specification the various features of the present invention have been described with relation to a specific embodiment thereof, as shown in the grease gun of the accompanying drawing, it will be apparent to those skilled in the art that the features of the present invention are adapted for use in grease guns which differ in construction from the one shown in the drawing.

I claim:

1. In a grease gun adapted for use selectively with cartridge-packaged greases and for both pressure and suction filling of bulk greases, said grease gun being of the kind having a cylindrical grease container with an integral wall, a closure cap removably mounted on the rear of said container, a grease dispensing head removably mounted on the front of said container, and a slidable plunger assembly within said container, the combination comprising a pair of annular blades of resilient, flexible material provided by said plunger assembly for sealingly engaging the inner wall of said grease container, one of said annular blades extending outwardly and rearwardly and the other of said blades extending outwardly and forwardly, the integral wall of said container toward the rear of said container being formed inwardly from the exterior thereof and providing an integral annular wall portion of greater inward extent than the wall of said container extending forwardly therefrom, said annular wall portion having at least a forward section and a rearward section, said forward section providing an inwardly converging surface merging smoothly at its forward end with the inside surface of said container wall, means for retracting said plunger assembly into the rearward portion of said container, said plunger assembly being retractable to a position where both of said annular blades are located rearwardly of the said forward section of said annular wall portion and adjacent the said rearward section thereof, said blades being depressable inwardly by engagement with said forward section to reduce the diameter of said plunger and being held in said depressed condition by said rearward section, and means for releasably locking said plunger assembly in said retracted position, whereby upon withdrawal behind the forward section of said annular wall portion said blades can be inserted in the open rear end of a grease cartridge.

2. The combination of claim 1 wherein said annular Wall portion also has an intermediate section providing an inner surface concentric with the inner surface of the forwardly extending portion of said container wall but spaced inwardly therefrom for holding the upper end of a grease cartridge in centered relation within said container, said intermediate section being located between said forward section and said rearward section.

3. The combination of claim 1 wherein said annular wall portion of said container also has an intermediate section providing an inner surface concentric with the inner surface of the forwardly-extending portion of said container wall but spaced therefrom for holding the upper end of a grease cartridge in centered relation within said container, said intermediate section being located between said forward section and said rearward section, and wherein said annular wall portion also provides an inwardly-projecting annular abutment located at the rearward end of said inner concentric surface in front of said rearward section for engaging the rear edge of a grease cartridge.

References Cited in the file of this patent UNITED STATES PATENTS 1,122,111 Hanson Dec. 22, 1914 1,472,123 Heinitsh et al. Oct. 30, 1923 1,702,619 Sargent Feb. 19, 1929 1,729,219 Kellogg Sept. 24, 1929 1,854,458 De Quincy et al Apr. 19, 1932 2,174,421 Krannak Sept. 26, 1939 2,361,126 Klein Oct. 24, 1944 2,612,296 Campbell et a1 Sept. 30, 1952 2,635,787 Bryant Apr. 21, 1953 2,759,640 Deupree Aug. 21, 1956 2,792,972 Deupree May 21, 1957 2,886,215 Klein et al. May 12, 1959 2,915,226 Sundholm Dec. 1, 1959 2,941,854 Jernander June 21, 1960