Abstract:
An in-line lubricator for a pneumatic tool system includes a body defining a fluid reservoir and a working passageway and an actuator positionable within the body. The actuator includes an elongated body having a transfer cavity formed therein which is in fluid communication with the fluid reservoir when the actuator is in a first position and which is in fluid communication with the working passageway when the actuator is in the second position. Movement of the actuator from the first position to the second position transports a predetermined amount of fluid from the fluid reservoir into the working passageway.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to systems for lubricating a pneumatically-driven power tool and specifically to an in-line lubricator configured to introduce a predetermined amount of lubricant into the compressed airflow which drives the motor.  
         BACKGROUND OF THE INVENTION  
         [0002]    Pneumatic tools such as screwdrivers, nailers and the like, generally comprise a body housing a pneumatic motor connected by a kinematic coupling to a drive member. The body includes a handle connected to a source of fluid under pressure and a trigger for controlling the entry of fluid, such as compressed air, to drive the motor.  
           [0003]    In many cases, it is desirable to introduce lubricant into the compressed air flow for lubricating the motor or other parts of the tool. A number of conventional arrangements provide lubrication consistently into the flow of air when the device is in operation. Often it is not desirable to provide a constant flow of lubrication into the components of the tool. Thus, an in-line lubricator which selectively introduces a metered amount of lubrication into the compressed airflow is needed.  
         SUMMARY OF THE INVENTION  
         [0004]    It is a general object of the present invention to provide a method and apparatus which provide an in-line lubricator for transferring a predetermined amount of fluid from a first location to a second location.  
           [0005]    In one form, the present invention provides an apparatus including a body defining a working channel and a fluid reservoir. The fluid reservoir contains lubricating fluid therewithin. The apparatus further includes an actuator having an elongated body including a transfer cavity. The transfer cavity is in fluid communication with the fluid reservoir in a first position. The actuator is movable to a second position whereby the transfer cavity dispenses a predetermined amount of lubricating fluid into the working channel.  
           [0006]    In another form, the present invention provides an arrangement for delivering a predetermined amount of lubricating fluid from a first location to a second location. The apparatus includes a body defining a working channel and fluid reservoir, the fluid reservoir containing lubricating fluid therewithin. The arrangement further includes a piston actuable between a first position and a second position. The piston includes a collection chamber in fluid communication with and operable to accumulate fluid from the fluid reservoir in the first position and dispense fluid therefrom into the working channel in the second position.  
           [0007]    Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limited the scope of the invention. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]    The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:  
         [0009]    [0009]FIG. 1 is a cutaway view of the in-line lubricator shown in the first position.  
         [0010]    [0010]FIG. 2 is a cutaway view of the in-line lubricator shown in the second position.  
         [0011]    [0011]FIG. 3 is a cutaway view of the in-line lubricator with the actuator removed.  
         [0012]    [0012]FIG. 4 is a side view of the actuator.  
         [0013]    [0013]FIG. 5 is a detailed view of the second end of the actuator. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0014]    The following description of the preferred embodiment is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.  
         [0015]    With initial reference to FIG. 1, the in-line lubricator according to the teachings of the present invention is illustrated and identified at reference numeral  10 . The in-line lubricator  10  generally includes a body  12  and actuator or piston  14 . As particularly shown, body  12  defines a first cavity or fluid reservoir  16  and a second cavity or working passageway  18 . As presently preferred, the volume of fluid reservoir  16  is approximately one-eighth (⅛) of an ounce.  
         [0016]    With continued reference to FIGS.  1 - 3 , the body  12  will be described in more detail. In the exemplary embodiment the fluid reservoir  16  contains a lubricating fluid such as oil and is oriented in a parallel relationship to the working passageway  18  which is configured to allow air flow therethrough. Working passageway  18  terminates at each end with threaded apertures adapted to receive a coupling for connecting the in-line lubricator between a compressor or other source of compressed air and a pneumatic tool. While in-line lubricator  10  is illustrated as a separate component from tool and compressor, one skilled in the art would recognize that the present invention could be configured as an integrated part of the tool and/or the compressor.  
         [0017]    With particular reference to FIG. 3, actuator  14  has been removed for illustrative purposes. A first bore  20  extends from an outer surface  26  of body  12  through an inner circumferential wall  28  of fluid reservoir  16  defining first and second diametrically opposed ports  30 ,  32 . First bore  20  further extends to an inner circumferential wall  38  of working passageway  18  defining a third port  34  thereat. A second bore  40  extends from outer surface  26  of body  12  to inner circumferential wall  38  of working channel  18  defining passage  44 . Second bore  40  is preferably aligned axially with first bore  20 .  
         [0018]    Actuator  14  will be further described referencing all figures. The actuator  14  is configured to axially slide through first bore  20  between a first position (FIG. 1) and a second position (FIG. 2). Actuator  14  is generally defined by elongated body  50 . First end  52  is defined by head  54  configured to receive handle  22  therearound. Handle  22  may be press fit onto head  54  or otherwise suitably secured to head  54  by a threaded connection or other like fastening means. First and second collars  56 ,  58  are axially separated by first neck  60 . A transfer cavity or collection chamber  66  is axially displaced from second collar  58  by second neck  68 . A second end  70  of elongated body  50  is defined by disk  72  which is axially displaced from collection chamber  66  by third neck  74 . A ridge  76  radially extends from disk  72  defining a step thereat to form a spring. Seat  78  as further described hereafter.  
         [0019]    First neck  60  includes a first O-ring  80  journalled therearound for engagement with circumferential wall  24  of first bore  20 . First O-ring  80  provides an interference fit between actuator  14  and circumferential wall  24  of bore  20  creating a seal therebetween. Second O-ring  82  provides an interference fit between actuator  14  and bore  20  when the actuator  14  is in the second position creating a seal therebetween to inhibit fluid flow from the fluid reservoir  16  to the working passageway  18 . Second O-ring  82  is disengaged from bore  20  in the first position. Third O-ring  84  provides an interference fit between actuator  14  and circumferential wall  36  of bore  20  when the actuator is in the first position creating a seal therebetween to inhibit fluid flow from the fluid reservoir  16  to the working passageway  18 . Third O-ring  84  is disengaged from bore  20  in the second position.  
         [0020]    Turning now to FIG. 5, collection chamber  66  is defined by the area between opposing radiused surfaces  86 ,  88  of ribs  90 ,  92 . Collection chamber  66  further includes an inner boundary defined by circumferential wall  94  and an outer boundary defined as circumferential wall  36 . Thus, the volume of collection chamber  60  is the annulus defined by radiused surfaces  86 ,  88  and circumferential walls  36 ,  94 . As presently preferred the volume of collection chamber  16  is approximately 0.001 in 3  or approximately the equivalent of one (1) drop of oil. However, One skilled in the art will recognize that the volume of collection chamber may be adjusted in accordance with the given application.  
         [0021]    Referencing FIG. 1, a spring  96  biases disk  72  into engagement with inner circumferential wall  38  of working channel  18  around third port  34 . Spring  96  is supported at one end by spring set  78  of disk  72  and at the opposite end by a threaded plug  98  disposed in passage  44  and axially biases actuator  14  in the first or closed position. Plug  98  is removable from passage  44  to provide access to working chamber  18  for assembly of in-line lubricator  10  and for drainage purposes or other maintenance needs.  
         [0022]    The operation of in-line lubricator  10  will now be described. Actuator  14  is linearly actuable from a first position (FIG. 1) to a second position (FIG. 2). To displace actuator  14  from a first position to a second position, the handle  22  is from a location laterally displaced from the outer wall  26  of body  12 , i.e. the first position to a location laterally engaged with outer wall  26 , i.e. the second position. While handle  22  is shown as a cylindrical disk, one skilled in the art will recognize that other geometrical configurations may be used or alternately a cantilever arm extending at various orientations relative to body  12  may be used.  
         [0023]    In the first position, fluid within the fluid reservoir  16  occupies the area defining collection chamber  66 . Fluid also fills an annular trough  74  bounded by third O-ring  84  and the circumferential wall  36  of bore  20  as represented by the flow arrows in FIG. 1. Accordingly, collection chamber  66  is filled with a volume of oil equal to one (1) drop as the actuator  14  is displaced from the first position to the second position until second O-ring  82  engages second port  32 . Displacement of actuator allows fluid contained in the collection chamber  66  to be emitted from third port  34  whereby the fluid is deposited into working passageway  18  upon disengagement of third O-ring  84  from third port  34 . When air flows through working passageway  18 , the oil spring  96  returns actuator  14  to the first position upon release of the handle  22 .  
         [0024]    The detailed description of the invention set forth above is merely exemplary in nature and, thus, the present invention may include variations that do not depart from the spirit and scope of the invention as defined in the appended claims.