Abstract:
A portable grease gun with the capability of being attached to either a grease containing barrel or a hose carrying grease from a grease supply container. An adapter may be mounted to the barrel mounting in place of a barrel to couple the grease gun to a hose connected to a grease supply container remote from the grease gun. Alternating plug may be mounted in the barrel mounting and a pumped grease supply coupled to the resupply port on the grease gun. The grease gun includes an output valve which restrains passage of grease at pressure below 30 psi.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application claims priority from provisional U.S. patent application Ser. No. 60/562,355 titled Multipressure Portable Grease Gun, filed on Apr. 15, 2004, and is a continuation-in-part of Ser. No. 11/104,819 filed Apr. 13, 2005 now U.S. Pat. No. 7,469,803 titled: Grease Gun with Remote-Feed Adapter. The disclosures of patent application Ser. No. 60/562,355, and Ser. No. 11/104,819 are hereby incorporated in their entireties. 

   BACKGROUND OF THE INVENTION 
   Portable grease guns are used throughout industry to provide a supply of pressurized grease to lubricate vehicles and myriad types of machinery. In the typical portable hand held grease gun, a grease gun body includes a screw mounting to which a grease “barrel”(a tube having one closed end and an open end) containing a quantity of grease or a grease cartridge may be attached to provide a source of grease for the grease gun. When the grease within the cartridge is exhausted, the barrel may be unmounted and a new cartridge inserted and the barrel remounted to the screw mounting of the grease gun body. Grease guns of this type are limited to use with a self contained grease barrel mounted to the grease gun body and carried with it. Such grease guns are useful when the user will need to move around a wide area to lubricate equipment zerks. 
   Other grease guns are provided with a coupling to a flexible hose connected to a grease supply which may rest on the ground or another surface and need not be carried by the user. Typical of such a grease supply is a container of bulk grease such as a pail or bucket or keg equipped with a hand operated or foot operated pump. As grease is needed in the grease gun body, the user pumps a charge of grease from the grease pail by operating the manual pump, thereby driving a supply of grease into the compression chamber of the grease gun. Existing grease guns of this nature allow for coupling to a grease hose only. This type of grease gun body is useful when the user may remain in a limited area while applying lubricating grease. 
   Existing hand held portable grease guns provided with removable grease gun barrel are provided with output check valves which resist pressure in the pressure chamber below about 25 psi so that grease under approximately 15 psi in the grease barrel will not discharge through the output nozzle. Resupply of the barrel through the standard resupply port on the grease gun body is limited to low pressure sources so that grease entering grease gun body through the resupply port will not be forced past the output check valve associated with the output nozzle. 
   A need exists for a versatile grease gun body which may be supplied by a grease barrel mounted on the gun body or by a larger supply of grease carried in a grease pail, barrel or keg and supplied to the grease gun barrel by a hose which may be coupled to the grease gun body. 
   A further need exists for a versatile grease gun which can be supplied through the standard resupply port at pressures exceeding 25 psi such as through a hose coupled to a grease reservoir pressurized by a foot pump. 
   The foregoing problems are addressed by the present grease gun invention. 
   BRIEF SUMMARY OF THE INVENTION 
   A portable grease gun is provided with the capability of being attached to either a grease containing barrel, or to a hose carrying grease from a grease supply container. The grease gun includes a threaded fitting which will receive a grease barrel which may be recharged through an inlet valve communicative with the interior of the grease barrel, or by replacing a cartridge within the barrel, or by suction from a bulk container. When the grease barrel is removed, an adapter may be substituted for the grease barrel which includes a fitting to which a hose may be mounted. The adapter includes external threads similar to those of the grease barrel, with the external threads receivable in the barrel mounting of the grease gun. The adapter includes a hose fitting which may be mounted opposite the barrel mounting. The hose fitting includes screw threads which will mate with a threaded hose fitting fixed to the end of a suitable hose for conveying grease from a pressurized grease pail, bucket, keg or other grease reservoir. 
   In an alternate embodiment, a grease gun body is provided with a plug element mounted to the barrel mounting to close the opening. The alternate embodiment grease gun also includes a fitting to couple a grease gun hose to the resupply port located on the grease gun body so that grease from a foot-pumped reservoir may be supplied on an ongoing process to the grease gun. 
   It is a primary object of the invention to provide a versatile portable grease gun which may be supplied from a self-contained pumped grease reservoir mounted directly to the grease gun or from a supply of bulk grease contained in a reservoir such as a pail, bucket, or keg. 
   It is also an object of the invention to provide a portable manually operated grease gun which may be used in applications where the grease gun operator is not required to move about a wide area as well as for applications where the user must carry the grease gun to various locations. 
   It is a further object of the invention to provide a grease gun barrel adapter which may be fitted to the barrel mounting of a grease gun provided with a barrel mount to adapt the grease gun for supplying grease from a bulk source via a duct or hose. 
   It is still a further object to provide a portable grease gun which can be supplied at the resupply port of the grease gun body through a hose coupled to a pumped reservoir of grease. 
   It is yet a further objective of the invention to provide a portable grease gun which may be supplied from a pumped grease supply through either the barrel mounting or the alternate fill port of the grease gun. 
   These and other objects will be understood upon review of the detailed description which follows. 

   
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       FIG. 1  is a front elevation of a grease gun according to the present invention, coupled by way of a hose to a grease reservoir. 
       FIG. 2  is a partial section of the grease gun of  FIG. 1  with parts of the handle and actuating lever cut away. 
       FIG. 3  is a front elevation of the invention grease gun with a grease barrel mounted thereto. 
       FIG. 4  is an elevation of an alternate grease gun system having a grease reservoir interconnect to a resupply port of a grease gun by a grease supply hose. 
       FIG. 5  is a partial section view of the grease gun body taken along line  5 - 5  of  FIG. 4 . 
   

   DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1  discloses a grease gun  2  according to the present invention, coupled by a flexible hose  4  to a grease reservoir  6 . The hose  4  joins grease gun  2  at adapter  8  which is removeably mounted to grease gun body  10 . In this configuration, grease from reservoir  6  may be forced by operation of first pump  7  through hose  4  and through adapter  8  into grease gun body  10 . This figure shows actuating lever  12  in its retracted position, rotated away from handle  14 . 
   Referring now to  FIG. 2 , a partial cross section of the grease gun  2  shows that adapter  8  is mounted to grease gun body  10  at barrel mounting  16  preferably by screw threads  9 . Barrel mounting  16  is configured to receive an end of a grease barrel but when a grease barrel is not mounted, adapter  8  may be screwed into barrel mounting  16 . Adapter  8  includes a hose coupling  18  which, as illustrated in  FIG. 2 , may receive a male coupling of a hose and a swivel connection. Adapter  8  provides a grease compartment  20  in which grease is stored until it is forced past inlet valve  22  into pressure chamber  24  of grease gun body  10 . Because adapter  8  is removable from grease gun body  10 , a conventional grease barrel may be mounted in its place in barrel mounting  16 . It should be understood that though a screw mounting is illustrated for barrel mounting  16 , other mechanical attachments such as a bayonet mount could be substituted for the screw mounting shown. 
   Adapter  8  is preferably cylindrical in shape with an open first end wall  11  which is communicative with the barrel mounting  16  and therefore with inlet port  15  of grease gun body  10 . First end wall  11  includes external screw threads for mating with internal screw threads of barrel mounting  16 . 
   Adapter  8  includes second end wall  17  which houses hose coupling  18 . Typically second end wall  17  will be smaller than first end wall  11 . Second end wall  17  houses hose coupling  18  and is preferably equipped with internal threads  19  to receive a conventional end coupler of a grease hose. 
   Nozzle body  34  of grease gun body  10  includes an output check valve spring  35  which biases ball  37  to close outlet port  39 . Check valve spring  35  is preferably selected to resist movement of ball  37  unless the pressure of grease in outlet port  39  exceeds approximately 150 psi though the pressure resistance of check valve spring  35  may be selected to provide resistance as low as about 30 psi. Increased check valve resistance is desired when grease is supplied to grease gun body  10  through a hose mounted to adapter  8  wherein grease pumped from a grease reservoir may easily exceed the pressure of grease in the conventional grease barrel  26  illustrated in  FIG. 3 . 
     FIG. 3  illustrates the grease gun  2  with a conventional grease barrel  26  mounted to barrel mounting  16  of grease gun body  10 . Grease barrel  26  typically may receive a 14.5 oz grease cartridge or it may be filled with bulk grease. As with conventional grease guns, grease within grease barrel  26  is forced into grease gun body  10  by a coil spring biased follower (not shown) contained within grease barrel  26 . The pressure of grease in a conventional grease barrel  26  typically does not exceed 16 psi. When the supply of grease in grease barrel  26  is exhausted, grease may be replenished within grease barrel  26  after plunger handle  28  is drawn from grease barrel  26  thereby compressing the coil spring within it. Grease can then be introduced through resupply port  30  (also known as the alternate filler port) mounted on grease gun body  10  which is communicative with the interior of grease barrel  26 . Resupply port  30  is capped when not in use. 
   An alternate embodiment of the invention is disclosed in  FIGS. 4 and 5 . Grease gun body  10  is provided with plug member  40  which is selectively received in barrel mounting  16 . Plug member  40  comprises a cylindrical sidewall  52  and bottom  54  joined thereto which together define hollow  50  therein. A hexagonal body  56  which is integral with bottom  54  depends from plug member  40 . Hexagonal body  56  may be grasped by a wrench to tighten plug member  40  within barrel mounting  16 . Hollow  50  provides a temporary storage reservoir for grease entering grease gun body  10  through resupply port  30 . Preferably, cylindrical sidewall  52  is provided with external threads  58  which are received by internal threads  57  in barrel mounting  16 . Therefore, a grease gun body  10  which may be supplied by a conventional grease barrel such as grease barrel  26  of  FIG. 3 , may be modified by removal of the grease barrel such that plug member  40  may be installed in barrel mounting  16 . Plug member  40  completely obstructs passage of grease through barrel mounting  16 . 
   Resupply port  30  is provided in grease gun body  10  and is ordinarily capped when the grease gun body is used conventionally such as when a grease barrel is mounted to grease gun body  10  at barrel mounting  16 . When plug member  40  is substituted for grease barrel  26 , resupply port  30  is uncapped and it may then be coupled to a remote source of grease. In the invention embodiment as disclosed in  FIGS. 4 ,  5 , an adapter fitting  41  may be selectively received in resupply port  30 . Grease supply hose  4  may be coupled to resupply port  30  of grease gun body  10  through hose coupler  43  which is joined axially to adapting coupling  59  which is joined in series to manually operated valve  44 . Manually operated valve  44  is in turn coupled to adapter fitting  41 . Manually operated valve  44  is interposed between hose coupler  43  and adapter  41  so that grease can be prevented from escaping when adapter fitting  41  is disconnected from resupply port  30 . 
   Nipple  62  of adapter fitting  41  is threaded into resupply port  30  which is conventionally provided with internal threads. Grease may be forced though an axial passageway  60  of adapter fitting  41  into resupply port  30  from grease reservoir  6  through hose  4  by action of first pump  7 . Grease entering resupply port  30  then may pass along internal passageway  61  of grease body  10  into hollow  50  of plug member  40  from which it can be drawn into the pressure chamber  24  of grease gun body  10 . 
   As with the preferred embodiment of  FIGS. 1 through 3 , because check valve spring  35  (see  FIG. 2 ) is selected to resist unseating of ball  37  unless pressure in outlet port  39  substantially exceeds at least 25 psi, grease at pressures well in excess of 16 psi may be introduced through resupply port  30  without leakage past output check valve ball  37  of nozzle body  34 . 
   The reason for removing the grease barrel  26  and plugging the barrel mounting  16  when supplying grease from a remote pump supply into the resupply port  30  is that the follower in the grease barrel  26  would not be able to seal against the pressure delivered by the pump  7 . There would be leakage around the plunger handle  28  the grease barrel  26 . 
   The foregoing description of the invention has been presented for purposes of illustration and description and is not intended to be exhaustive or to limit the invention to the precise form disclosed. Modifications and variations of the embodiments are possible in light of the above disclosure or such may be acquired through practice of the invention. The embodiments illustrated were chosen in order to explain the principles of the invention and its practical application to enable one skilled in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto, and by their equivalents.