Abstract:
A grease gun cylinder walled cartridge adapted for direct attachment to any of a variety of grease gun head constructions and grease pumping systems, wherein the cartridge wall can be of any color or completely clear and see through, wherein the grease column within the cartridge is pressured toward and through an inlet port in the gun head, which port opens on the section stroke of a piston mounted in said cylinder into a loading portion of a cylinder of the grease pumping system, and wherein the grease column pressuring means is ambient air pressure.

Description:
FIELD 
       [0001]    The present invention resides in the structure of a grease gun cartridge adapted for use on a grease gun having any of a wide variety of grease gun pump constructions, typical of which pump constructions are shown in the drawings herein and in U.S. Pat. Nos. 3,338,478; 3,344,084; 2,978,151; 1,368,840; 1,349,994; and 4,601,412, the disclosures of which are hereby incorporated herein by reference in their entireties. 
         [0002]    The typical mechanism in the gun head for operating these prior grease gun pumps consists of a grease loading and ejection cylinder in which a piston is slidably mounted for reciprocation between a grease loading stroke and a grease pressurizing (ejection) stroke, back and forth across a grease inlet port on the gun head, which port is in communication with the grease loading and ejection cylinder in the head. The inlet port is also in communication with a grease reservoir (cartridge) positioned in a metal barrel which is affixed to the gun head. In these mechanisms the grease in the loading operation is pressurized by a cartridge piston, a cartridge piston cocking rod, and a compression spring means having one end bearing against the lower inner end of the barrel (not shown) and having its other end bearing against the lower end of the piston within the filled cartridge and pressurizing the grease column within the cartridge toward and through the inlet port and into the grease loading cylinder. The piston in the gun head closes off the inlet port on its pressurizing (ejection) stroke and forces the grease, which was forced into the loading and ejection cylinder through the inlet port on the piston suction stroke by means of the cartridge spring, out of the gun head on the ejection (pressurizing stroke) and through a hose to a ZERK or equivalent fitting. One-way valving opens the loading and ejection cylinder to the hose on the piston ejection stroke and closes off the cylinder to the hose on the ejection piston suction stroke. Hand operated lever means or dual handle means operates the back and forth reciprocating action of the piston. 
       SUMMARY OF THE INVENTION 
       [0003]    A grease in cylindrically walled cartridge adapted for direct attachment to any of a variety of grease gun head constructions having any of a variety of grease pumping systems, wherein the cartridge wall can be of any color or completely clear and see through, wherein the grease column within the cartridge is pressured toward and through an inlet port in the gun head, which port opens on the suction stroke of a piston mounted in said cylinder into a loading portion of a cylinder of the grease pumping system, and wherein the grease column pressuring means comprises ambient air pressure impinging on the bottom surface of a grease column. 
         [0004]    It is particularly noted that in the above recited cartridge structure there is no metal barrel for containing the cartridge, no spring urged piston, no grease pressurizing spring, and no piston cocking rod. This structure reduces the operational effort required for use of the present cartridge to near zero as compared to the heretofore, required effort of:
       (1) retracting a cocking rod against the force of the heavy barrel spring and locking it to the metal barrel end;   (2) unscrewing the barrel from the gun head which is often a slippery and difficult experience;   (3) removing the greasy spent cartridge from the metal barrel;   (4) uncapping the bottom end of a filled replacement cartridge;   (5) placing the open bottom end of the replacement cartridge into the barrel;   (6) removing the top metal cover of the cartridge;   (7) screwing the metal barrel into the gun head; and   (8) pushing the cocking rod back through the cartridge piston and locking the rod to the bottom barrel end.       
 
         [0013]    It is particularly noted that the above multiplicity of steps are being done with the greasy cocking rod extending about a foot beyond and waving obtrusively about the bottom end of the barrel. The present invention eliminates this onerous procedure and in particular renders the grease gun user friendly. All that is required is to pick up the cartridge shown, e.g., in  FIG. 3A  and screwing its top into the mounting socket of the grease gun. 
     
    
     
         [0014]    The invention will be further understood from the drawings herein the various figures are not necessarily drawn to scale or consistent proportions, and wherein: 
           [0015]      FIG. 1  is a side view of one preferred embodiment of the present non conventional cartridge wherein the mounting threads are integrally molded with the top of the cartridge wall; 
           [0016]      FIG. 2  is a proximal end view of the cartridge of  FIG. 1  taken along line  2 - 2  in  FIG. 1 ; 
           [0017]      FIG. 3  is a longitudinal cross-sectional view taken alone line  3 - 3  in  FIG. 1 ; 
           [0018]      FIG. 3A  is a perspective, partially cross-sectioned view of an assembly of the present non-collar cartridge of  FIGS. 1-3  (having integrally molded mounting threads), and a conventional grease gun head; 
           [0019]      FIG. 4  is a side view of a cartridge mounting collar used on conventional grease cartridges; 
           [0020]      FIG. 5  is a proximal end view taken along line  5 - 5  in  FIG. 4 ; 
           [0021]      FIG. 6  is a cross-sectional view taken along line  6 - 6  in  FIG. 4 ; 
           [0022]      FIG. 6A  is an enlarged cross-section of a collar type of cartridge-to-gun head mounting structure; 
           [0023]      FIG. 6B  is a view as in  FIG. 6A  and additionally showing a typical grease gun head and grease pumping system; 
           [0024]      FIG. 7  is a side view of the primer bulb housing; 
           [0025]      FIG. 8  is a distal end view taken along line  8 - 8  in  FIG. 7 ; 
           [0026]      FIG. 8A  is an enlarged view of  FIG. 8 ; 
           [0027]      FIG. 9  is a cross-sectional view taken along line  9 - 9  in  FIG. 7 ; 
           [0028]      FIG. 10  is an end view taken along line  10 - 10  in  FIG. 9 ; 
           [0029]      FIG. 11  is an enlarged cross-sectional view of the dotted (in  FIG. 3 ) snap-in region of the primer structure into the cartridge bottom ends; 
           [0030]      FIG. 12  is a longitudinal cross-section of a variation of the primer structure; 
           [0031]      FIG. 13  is an end view taken along line  13 - 13  in  FIG. 12 ; 
           [0032]      FIG. 14  is an end view taken along hug  14 - 14  in  FIG. 12 ; 
           [0033]      FIG. 15  is an alternative primer structure to that shown in  FIGS. 1-3  wherein it is particularly useful with cartridges having irregularities such as longitudinal grooves in its inner wall surfaces; 
           [0034]      FIG. 16  is an end view taken along line  16 - 16  in  FIG. 15 ; 
           [0035]      FIG. 17  is an enlarged view of dotted area “A” in  FIG. 15 ; 
           [0036]      FIG. 18  is a side view of an alternative primer structure; 
           [0037]      FIG. 19  is a view taken along line  19 - 19  in  FIG. 18 ; 
           [0038]      FIG. 20  is a cross-sectional view taken along line  20 - 20  in  FIG. 18 ; 
           [0039]      FIG. 21  is a view of the metal grip ring; and 
           [0040]      FIG. 22  is a side view of the grip ring of  FIG. 21 . 
       
    
    
     DETAILED DESCRIPTION 
       [0041]    By contrast to prior grease guns, in the present cartridge invention which can be used on any of the gun heads and grease pumping mechanisms presently available and/or as shown in the above noted patents, the present grease cartridge has no metal barrel, no spring urged piston, no piston cocking rod, and no grease pressurizing spring means for forcing the grease toward and through the inlet port and into the loading cylinder. With the present cartridge, the only force which is applied against the bottom end of the grease column within the present cartridge is air pressure provided by ambient air which is in communication with the bottom end of the grease column through one or more air bleed apertures or valving formed through wall portions of the cartridge at locations situated below the bottom end of the grease column and which enters into an ambient air chamber  40 . Where the pumping mechanism of the grease gun does not provide adequate suction (not typical) in the loading cylinder to become self priming when using the present cartridge, a priming device such as the priming bulb shown, for example, in accompanying  FIGS. 8-13  may be used to temporarily provide a small additional air pressure to the bottom of the grease column. It is noted that in the conventional off-the-shelf grease cartridges on the market, the bottom of the grease column does not extend to the bottom end of the cartridge such as to provide a lead-in portion of the cartridge wall for entry of the grease pressurizing piston which is mounted on the cocking rod. This lead-in portion provides space for the introduction of the present wiper disc and auxiliary primer and one-way valving structures. 
         [0042]    As shown in  FIGS. 3A and 6B , the typical grease gun head  18  is provided with an annular mounting socket  16  the side wall of which is internally threaded for receiving the externally threaded end of a metal grease cartridge containing barrel (not shown). The present cartridge  10 , preferably of molded plastic, is threaded at its distal upper end  30  for threading into the conventional mounting socket  16  and sealing against a sealing surface of the socket, which sealing surface, preferably, comprises an annular elastomeric gasket  20 . Alternatively, the seal can be the elastomeric deformable distal (upper) distal end  30  of the cartridge wall itself sealing against the roof  22  of socket  16 . 
         [0043]    The grease guns having utility with the present invention include those as shown in  FIGS. 6B and 3A , haying the conventional structures of gun head  18 , pump handles or lever  79 , grease hose  80 , ZERK fitting  81  and the like, and the grease pumping system having piston (loading) cylinder  82 , piston  83 , grease inlet port  84  to  82 , handle or lever actuating linage  85 , and grease outlet port  86  with one-way valving  88 . 
         [0044]    In the embodiment shown in  FIGS. 4-6B , an annular collar  78  is dimensioned for a close sliding fit on the cylindrical cartridge wall  12  and is formed with an annular upper surface  91  for sealingly engaging the undersides  93  of the annular lip  92 , formed, e.g., during molding or curling the distal (upper) end  30  of a fabricated or molded plastic cartridge and, by threading said end into the mounting socket and forcing the upper surface  90  of cartridge lip  92  into sealing engagement with the roof  22  or seal  20  of the mounting socket  16 . 
         [0045]    Referring to  FIGS. 1-3  of the drawings the present cartridge  10  in a non-collar embodiment, is preferably, of molded industrial plastic material such as, polyolefin&#39;s, polyurethane, polyester, polyimide, polycarbonate or various copolymers, comprises a cylindrical wall  12  having a threaded top end  14  adapted to be screwed into a mounting socket  16  of a grease gun head  18  and preferably sealed against an annular elastomeric seal  20  fitted against the roof  22  of socket  16 . Grease  24  initially fills cartridge chamber  26  to a desired level and forms a grease column  28  extending between the upper end  30  of the cartridge and the top  32  of a wiper disc  34  of slippery plastic material should such a disc be used. The wiper disc is not critical to the operation of the present cartridge but can assist in distributing the ambient air pressure “P” evenly against the bottom end surface  38  of the grease column. Also, the disc eliminates or at least minimizes any rogue grease migration which might occur down along the lower inner side portions of wall  12  and into the ambient air chamber  40 . The air pressure in chamber  40  is maintained substantially constant by one or more air bleed ports  42  which can be provided in any portion of wall  12  which wall includes end cap portion  36 , which portions below the bottom end surface  38  of the grease column  28 . As shown in  FIG. 1 , a removable cap  76  is pushed or screwed down over the threaded end of the cartridge to contain the grease and to protect the threads at end  14  prior to use of the cartridge. 
         [0046]    In a preferred embodiment of the use of a primer device, the air bleed port  42  is provided by way of a primer structure  45  having a primer housing  47  as shown in detail in  FIGS. 9-11   15 ,  16  and  17  wherein a primer bulb section  41  comprises a body portion  43  having a resilient elastomeric squeeze bulb  44 , a first annular stop shoulder  46  and a second annular stop shoulder  48  having an annular beveled lead-in surface  50 . Said body portion  43  being formed with a one way valve section  52  comprising lips or flaps  54  and  56  which form slit  51  which is normally tightly, sealingly closed as shown e.g., in  FIGS. 8 and 9 , but which opens as shown by dotted line  58  in  FIG. 8A  upon squeezing bulb  44  to force air through slit  51 . Primer structure  45  in  FIGS. 8-11  further comprises a. mounting cap or body  60  having an annular snap on flange  62  having, e.g., 3-8 spurs  64  raised outwardly on its outer surface, wherein both the flange and the spurs will spring outwardly to nest the spurs into slots  66  in cartridge wall  12  upon flange  62  being forcibly pushed and flexed radially inwardly into the bottom end  68  of the cartridge wall wherein annular rim  70  on flange  62  will engage the bottom end  68  of cartridge wall  12  to properly position structure  45  within the cartridge. 
         [0047]    Cap  60  ( FIG. 11 ) is formed with a primer bulb mounting aperture  72  formed in wall  73  of the cap  60  and through which aperture the bulb section  41  is pushed ( FIG. 9 ) to engage beveled leading edge surface  50  with aperture  72  edges to cam body portion  43  radially inward to snap and lock bulb section  41  into wall  73  between shoulders  46  and  48  of section  41 . 
         [0048]    It is noted that grease cartridge tubes presently on the market have on one end a removable, tear away metal top closure member which is provided with a finger pull tab for easy tear removal of the closure member. A removable cap is positioned over the bottom end of the cartridge. In using such off-the-shelf cartridges in accordance with the present invention, the bottom cap is removed and the alternative to  FIGS. 1-3  if a primer is to be used, a primer housing  47  ( FIGS. 15-17 ), is pushed up into the bottom end  68  of the cartridge against elastomeric seal  69  and then rotated slightly by finger grips  71 , e.g., 1/32 to ⅛ of an inch to score wall  12  and lock the metal points  77  which are molded into the primer housing wall  75 , into the cartridge wall  12 . Where a primer is not used, the primer housing  47 , without the primer bulb section  41  and one way valving section  52  is replaced with an ambient air bleed port  42 . The cartridge wall  12  may be provided with any indicia such as grease level markings  87 , manufactures notations, or grease type or the like. 
         [0049]    Referring to  FIGS. 19-22 , a highly preferred embodiment of the primer/one way air valve  95  is shown wherein housing or end cap  96  is provided with an O-ring type seal  100  or an equivalent seal or a sealing compound which will prevent leakages of grease from the bottom end of the cartridge even though there might be irregularities in the inner surface of the cartridge wall which otherwise could form grease leakage channels. The mechanical properties of the seal should provide for conformation of the seal to the configuration of substantial irregularities. 
         [0050]    Further, housing  96  is provided with an annular grip ring which is formed with sharp edged gripping teeth  99  which will flex inwardly against the housing wall as the housing is being forced into the bottom end of the cylinder until it is stopped by engagement of annular rim  98  with the cartridge bottom end. At this point, the teeth ends will be in engagement with and will bite into the inner wall of the cartridge and prevent extraction of the housing from the cartridge. In assembling the ring onto the housing, the ring is forced over the air outlet end of the housing whereby the housing wall will resiliently flex radially inwardly sufficiently to allow the ring to slide into the annular groove as shown in  FIG. 20 . 
         [0051]    The invention has been described in detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications will be effected within the spirit and scope of the invention.