Abstract:
An improved motorized lubricant dispenser comprising a multi-port rotary distributor disconnectably connected to a detachable motorized lubricant dispenser. The multi-port rotary distributor is connectable to a plurality of lubrication points. The multi-port rotary distributor has a compact size and is essentially comprised of three parts: (1) a manifold; (2) a closure cap; and (3) a distributor disk. The detachable motorized lubricant dispenser has an electric motor-driven spindle that floatingly engages and rotatingly drives the distributor disk of the multi-port rotary distributor. As the distributor disk rotates, an aperture in the distributor disk successively registers with each of the discharge ports of the rotary distributor manifold to allow lubricant, which is pressurized by the advancing piston in the motorized lubricant dispenser, to flow out successively to each of the lubrication points that are connected to the multi-port rotary distributor.

Description:
FIELD OF THE INVENTION  
         [0001]    The invention relates to a multi-port, motorized lubricant dispenser. More particularly, the invention relates to a multi-port lubricant dispenser having a multi-port rotary distributor disconnectably connected to a detachable motorized lubricant dispenser.  
         BACKGROUND  
         [0002]    Industrial machinery, including industrial robots, commonly require the application of fluent lubricants at joints and other areas where adjacent surfaces or contact points are in contacting relative motion. Because of its great importance to industrialized society, the provision of lubricants to each point on a machine which needs to be lubricated, i.e., to “lubrication points,” is an old and crowded art.  
           [0003]    Modernly, it is known to use self-contained, lubricant dispensers to supply lubricant to satisfy many lubrication needs. These lightweight units have the advantage of being installable local to the joint that is to be lubricated. This obviates the need to resort to either manual lubrication or the use of long lubricant distribution lines from a remote supply of lubricant.  
           [0004]    Some of such lubricant dispensers are motorized units having a two-part housing. The lower part comprises a vessel adapted to hold a supply of lubricant on the order of a few tens to a few hundreds cubic centimeters and is formed to neck down to an outlet adapted to threadably attach to a fitting on the machine that is in communication with the lubrication point that is to be lubricated. The upper part comprises an upper housing containing an electric motor drive, a threaded spindle, and a piston arranged so that periodically energizing the electric motor drive causes the spindle to advance the piston into the lubricant reservoir of the lower part, thereby displacing lubricant from the reservoir to a lubrication point on the machine that is to be lubricated. Examples of such motorized lubricant dispensers are described in U.S. Pat. No. 5,271,528 to Chien, U.S. Pat. No. 5,634,531 to Graf et al., and U.S. Pat. No. 5,971,229 to May et al. The teachings of each of these patents are incorporated herein by reference.  
           [0005]    Gas pressure driven lubricant dispensers are also known. The gas pressure driven units are similar to their motorized counterparts except that instead of using an electric motor drive and spindle to drive the piston that displaces the lubricant from the reservoir, the gas pressure driven units typically contain in their upper sections a two-part chemical system which, when activated, creates a gas pressure for driving the lubricant-displacing piston. Examples of gas pressure driven lubricant dispensers are described in U.S. Pat. No. 5,386,883 to Graf and U.S. Pat. No. 5,409,084 to Graf. The teachings of each of these patents are incorporated herein by reference. Many gas pressure driven lubricant dispensers, however, suffer from a deficiency not present in the motorized units in that the pressurization reaction they employ is not reversible. Thus, such a gas pressure driven unit will continue providing lubricant even when the machine is out of service, thereby wasting its lubricant, depleting its gas pressure, and possibly creating a mess of excess lubricant in the vicinity of the joint to which it is supplying lubricant.  
           [0006]    The presently known motorized lubricant dispensers are not without their own drawbacks. One disadvantage that is of considerable importance is that a separate lubricant dispenser is needed for each lubrication point. This is problematic because it is necessary to provide clearance around and access to each lubricant dispenser. This is especially problematic when two or more lubrication points are in such close proximity to one another that there is insufficient room to install the corresponding lubricant dispensers so close to each other or when the machine&#39;s design or operation provides little space to accommodate a lubricant dispenser in the vicinity of each lubrication point. Another disadvantage is the cost of providing and maintaining a separate electric motor drive in each motorized lubricant dispenser. Yet another disadvantage is that, in some instances, a motorized lubricant dispenser may provide more lubricant than is needed by the lubrication point and cause a mess of excess lubricant in the vicinity of the lubrication point.  
         SUMMARY OF THE INVENTION  
         [0007]    The present invention overcomes the disadvantages of the prior art motorized lubricant dispensers by providing an improved multi-port lubricant dispenser comprising a multi-port rotary distributor disconnectably connected to a detachable motorized lubricant dispenser. The multi-port rotary distributor is connectable to a plurality of lubrication points. The detachable motorized lubricant dispenser has an electric motor-driven spindle that floatingly engages and rotatingly drives a distributor disk within the multi-port rotary distributor. In service, as the distributor disk rotates, an aperture in the distributor disk successively registers with each of the discharge ports of the rotary distributor manifold to allow lubricant, which is pressurized by the advancing piston in the motorized lubricant dispenser, to flow out successively to each of the lubrication points that are connected to the multi-port rotary distributor. The multi-port rotary distributor takes full advantage of the limited amount of lubricant pressure which the motorized lubricant dispenser delivers by substantially placing only one discharge port at a time in communication with the pressurized lubricant reservoir.  
           [0008]    One of the advantages of the present invention is the space-savingly compact and simple design of the multi-port rotary distributor. The multi-port rotary distributor is essentially comprised of three parts: (1) a manifold; (2) a closure cap; and (3) a distributor disk. Although a spring may be optionally interposed between the closure cap and the distributor disk to assist in keeping the distributor disk in place, during operation it is the force of the pressurized lubricant that keeps the distributor disk seated on the manifold face.  
           [0009]    The multi-port rotary distributor contributes very little to the overall height of the multi-port lubricant dispenser as its height is only a fraction of that of the motorized lubricant dispenser. Preferably, the axial height of the multi-port rotary distributor is about a third or less than the axial height of the motorized lubricant dispenser to which it connects. The multi-port rotary distributor also has a small maximum outside diameter which is preferably smaller than that of the maximum outside diameter of the lubricant dispenser.  
           [0010]    The shape of the closure cap may be generally cylindrical or, more preferably, it may taper out from a narrow inlet adapted to connect to the motorized lubricant dispenser to a wider base adapted to connect to the manifold. A tapered shape for the closure cap helps to minimize the size and the mass of the multi-port distributor while promoting good flow of the lubricant. Because of the small size of the multi-port rotary distributor, the inertial mass of an improved multi-port motorized lubricant dispenser according to the present invention is comparable to that of a single conventional motorized lubricant dispenser. When it is taken into consideration that an improved multi-port lubricant dispenser according to the present invention can take the place of multiple conventional lubricant dispensers, it is clear that in applications such as robot arms where the lubricant dispenser is installed on a moving part, the present invention provides the advantage of reducing the moving mass by significantly reducing the overall inertial mass attributable to lubricant dispensers on the moving part thereby yielding energy savings and permitting the use of smaller drive units for moving the parts.  
           [0011]    Another advantage of the present invention is the floating engagement of the spindle of the motorized lubricant dispenser with the distributor disk of the multi-port rotary distributor. By floating engagement it is meant that although the spindle positively engages the distributor disk to rotationally drive the distributor disk, the spindle does not engage the distributor disk in the axial direction in a manner which presses the distributor disk against the manifold face. Thus, the spindle length does not have to be precisely fitted to the multi-port distributor in order to avoid compromising the operation of the unit by the spindle causing the distributor disk to press too hard or not hard enough against the manifold face. This floating engagement feature of the present invention not only makes it easy to detach and reattach the motorized lubricant dispenser from the multi-port rotary distributor, for example, for the purpose of refilling the lubricant reservoir of the lubricant dispenser, but it also facilitates replacing one motorized lubricant dispenser with another since axial dimension fitting concerns are greatly reduced.  
           [0012]    Another advantage of an improved multi-port lubricant dispenser according to the present invention is that it is less expensive to manufacture than the multiple conventional lubricant dispensers which it replaces. Yet another advantage is that, by distributing lubricant to multiple lubrication points instead of just one lubrication point, an improved multi-port lubricant dispenser according to the present invention reduces the chance that excess lubricant will be provided to any lubrication point to cause a mess of wasted lubricant.  
           [0013]    Thus, it is an object of the present invention to provide an improved multi-port motorized lubricant dispenser that can be used in place of multiple conventional single-point lubricant dispensers, even on moving parts such as robot arms.  
           [0014]    It is also an object of the present invention to provide an improved multi-port lubricant dispenser comprising a multi-port rotary distributor which may be left in place connected to multiple lubrication points on a machine that is to be lubricated and a detachable motorized lubricant dispenser which may be removed for refilling and reattached to the multi-port rotary distributor or be substituted for by a replacement motorized lubricant dispenser.  
           [0015]    It is noted that the use of rotary distributors to distribute lubricant to multiple lubrication points has long been known in the art. Some examples of rotary distributors so employed are described in U.S. Pat. No. 768,529 to King, U.S. Pat. No. 1,862,164 to Sheppard, U.S. Pat. No. 1,886,067 to Moses, U.S. Pat. No. 1,887,199 to Gillam, U.S. Pat. No. 2,481,856 to Medhaug, U.S. Pat. No. 2,546,585 to Caldwell, U.S. Pat. No. 3,217,835 to Settles, U.S. Pat. No. 4,147,233 to Smith, U.S. Pat. No. 4,286,691 to Stong, and U.S. Pat. No. 5,181,585 to Braun et al. The teachings of each of these patents are incorporated herein by reference. However, one skilled in the art will recognize that what is not described by any of these patents nor is otherwise known in or suggested by the art is a multi-port motorized lubricant dispenser having all of the aforementioned features and advantages of the present invention. These and other features and advantages inherent in the subject matter claimed and disclosed will become apparent to those skilled in the art from the following detailed description of presently preferred embodiments thereof and to the appended drawings.  
         BRIEF DESCRIPTION OF THE DRAWINGS  
         [0016]    The criticality of the features and merits of the present invention will be better understood by reference to the attached drawings wherein similar reference characters denote similar elements throughout the figures. It is to be understood, however, that the drawings are designed for the purpose of illustration only and not as a definition of the limits of the present invention. 
       
    
    
       [0017]    [0017]FIG. 1 is a perspective view of a multi-port lubricant dispenser according to a first embodiment of the present invention.  
         [0018]    [0018]FIG. 2 is an exploded view of a multi-port lubricant dispenser according to a second embodiment of the present invention showing the multi-port lubricant dispenser in cross-section along an axial mid-plane.  
         [0019]    [0019]FIG. 3 is a cross-sectional view taken along an axial mid-plane of the lower portion of the embodiment shown in FIG. 2.  
         [0020]    [0020]FIG. 4 is a top view of the manifold of the embodiment shown in FIG. 3.  
         [0021]    [0021]FIG. 5 is a top view of the distributor plate of the embodiment shown in FIG. 3. 
     
    
     DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0022]    A multi-port lubricant dispenser  10  according to an embodiment of the present invention is illustrated in FIG. 1. The multi-port lubricant dispenser  10  comprises a detachable motorized lubricant dispenser  12  and a multi-port rotary distributor  14  which are threadably joined together at junction  16 . Motorized lubricant dispenser  12  has a two-part housing comprising upper housing  18  and tapered lower housing  20 . Multi-port rotary distributor  14  includes tapered closure cap  22  and manifold  24 . Manifold  24  is adapted to receive a plurality of fittings  26  each of which communicates with a lubrication point on a machine that is to be lubricated by the multi-port lubricant dispenser  10 .  
         [0023]    A second embodiment of a multi-port lubricant dispenser  10  according to the present invention is illustrated in FIG. 2 as an exploded view showing a cross-section thereof along an axial mid-plane. This second embodiment differs from the first embodiment shown in FIG. 1 only in that the size of the multi-port rotary distributor  14  is relatively larger in the second embodiment. In the first embodiment, the maximum outside diameter  28  of the multi-port rotary distributor  14  is shown as being smaller than the maximum outside diameter  30  of the motorized lubricant dispenser  12  whereas in the second embodiments, these diameters are shown as being about equal to each other. Because this is the only difference between these two embodiments, the same reference numerals are used in describing both embodiments without distinction.  
         [0024]    Referring to FIG. 2, motorized lubricant dispenser  12  comprises upper housing  18 , lower housing  20 , electric drive unit  32 , piston  34 , spindle  36 , lubricant reservoir  38 , gaskets  40 , lower housing neck  42 , and reservoir outlet  44 . The upper housing  18  and lower housing  20  connect together by means of upper housing inner threads  46  engaging lower housing outer threads  48 . Lower housing  20  tapers down to neck  42  and terminates at reservoir outlet  44 . Piston  34 , which is fitted with one or more gaskets  40 , is disposed within lower housing  20  so as to be axially movable therein, but is restrained from rotating by the friction between gaskets  40  and lower housing inner surface  47 . Lower housing inner surface  47  and lower surface  49  of piston  34  define lubricant reservoir  38 .  
         [0025]    Electric drive unit  32 , which is shown schematically, is housed within upper housing  18  and may be accessed by disconnecting upper housing  18  from lower housing  20 . Electric drive unit  32  comprises an electric motor  50  and an output transmission  52  for driving spindle  36 . Electric drive unit  32  optionally includes a control circuit  54  for operating the electric motor  50 . The control circuit  54  preferably includes a timing circuit  56  operable to periodically activate the electric motor  50  to cause it to rotate the spindle  36 . Preferably, the electric motor  50  is battery powered and electric drive unit  32  further comprises a battery  58  for powering the electric motor  50  and other electronic components of the electric drive unit  32 . Power from an outside source may also be used instead of or as a supplement to battery  58 .  
         [0026]    Socket  60  of electric drive unit  32  engages faceted head  62  of spindle  36 . Spindle  36  is threaded through piston  34  so that rotating spindle  36  causes piston  34  to advance into or to retreat out from lubricant reservoir  38 . Advancing piston  34  into lubricant reservoir  38  displaces lubricant from lubricant reservoir  38  and causes the lubricant to flow out through reservoir outlet  44 . Retreating piston  34  out from lubricant reservoir  38  permits the lubricant reservoir  38  to be refilled with lubricant. Spindle  32  extends out through reservoir outlet  44  and terminates with planar tip  64 .  
         [0027]    Multi-port rotary distributor  14  comprises tapered closure cap  22 , distributor disk  66 , and manifold  24 . Preferably, each of these components is formed as a monolithic part. Closure cap  22  and manifold  24  connect together by means of closure cap inner threads  68  engaging manifold outer threads  70 . Closure cap  22  narrows into closure cap neck  72  which is adapted to receive lower housing neck  42  of motorized lubricant dispenser  12 . Referring to FIG. 3, closure cap  22  and manifold  24  define lubricant receiving space  74  within multi-port rotary distributor  14 .  
         [0028]    As shown in FIG. 2, manifold  24  has a cylindrical cavity  76  formed by walls  78  and manifold face  80 . Referring to FIG. 4, manifold face  80  contains a plurality of openings  82 . Referring now to FIG. 3, each of the openings  82  is part of one of a plurality of manifold outlets  84 . Each of the manifold outlets  84  is adapted to receive a fitting or line which communicates with a lubrication point that is to be lubricated by the multi-port lubricant dispenser  10 .  
         [0029]    Referring to FIGS. 2 and 3, distributor disk  66  is positioned in cavity  76  of manifold  24  so that distributor disk lower face  86  seats upon manifold face  80 . Distributor disk  66  comprises circular plate  88  and axial stem  90 . It is to be understood that the circular plate  88  may be of constant or varied thickness. Axial stem  90  has at its distal end a slot  92  for receiving a planar tip  64  of spindle  36 . Slot  92  and planar tip  64  cooperate to provide for floating engagement of distributor disk  66  by spindle  36 . Thus, spindle  36  is able to rotatingly drive distribution disk  66  without pressing distributor lower face  86  against manifold face  80 .  
         [0030]    As shown in FIG. 5, circular plate  88  contains an aperture  94 . As spindle  36  rotates distributor disk  66 , aperture  94  successively registers with each of the openings  82  to place the corresponding manifold outlet  84  in fluid communication with the lubricant receiving space  74 . This causes the pressurized fluent lubricant which was displaced into the lubricant receiving space  74  from lubricant reservoir  38  by the advancement of piston  34  to flow out through aperture  94  and opening  82  into the fitting or line that is attached to the corresponding manifold outlet  84  and subsequently to flow to a lubrication point. FIG. 3 shows aperture  94  in such registration with an opening  82   a  while the other openings  82 , such as opening  82   b , are closed off by circular plate  88 .  
         [0031]    Referring to FIG. 5, the dimensions of aperture  94 , in particular the width  96  and arc length  98 , may be chosen to regulate the amount of lubricant that is to be delivered at each registration of the aperture  94  with an opening  82 . Preferably, the arc length  98  is restricted so that aperture  94  only registers with one opening  82  at a time. However, it is also contemplated that the leading edge  100  of aperture  94  may begin to register with one opening  82  before the trailing edge  102  of aperture  94  has completed its registration with the previous opening  82 . This arrangement tends to keep the delivery pressure of the lubricant from pulsating during the lubrication operation.  
         [0032]    One skilled in the art will recognize that the size and angular spacing of openings  82  will influence the amount of lubricant delivered to a corresponding lubrication point by each registration of aperture  94  with an opening  82 . Although all of the openings  82  preferably are of the same size and the angular spacing between adjacent openings  82  preferably is uniform, the present invention also contemplates that the relative sizes and angular spacings may be varied to suit the needs of a particular lubrication application.  
         [0033]    Although the dimensions and the materials of construction of the multi-port rotary distributor  14  may be varied widely depending on the application and the particular lubricant used for the application, it is preferred that the multi-port rotary distributor  14  be constructed in a manner that minimizes its cost and/or its inertial mass. Preferably, closure cap  22 , distributor disk  66 , and manifold  24  are made of low-cost materials, for example without limitation, plastics or metals. For example without limitation, one or more of these components may be made of steel or stainless steel. More preferably, one or more of these components is made of a low density material, for example, without limitation, aluminum or plastic.  
         [0034]    The embodiments illustrated in FIGS.  1 - 3  show the lower housing  20  of the motorized lubricant dispenser  12  and the closure cap  22  of the multi-port rotary distributor  14  each to taper to a cylindrical neck, i.e., lower housing neck  42  and closure cap neck  72 , respectively. It is not necessary, however, for both or either of lower housing  20  or closure cap  22  to have a cylindrical neck so long as these two components are adapted to disconnectably connect, either directly or by means of an intermediate connector, the motorized lubricant dispenser  12  to the multi-port rotary distributor  14 . Additionally, although tapering of the shapes of these components is beneficial in promoting lubricant flow, these components may take on other shapes, such as, without limitation, cylindrical shapes.  
         [0035]    The operation of a multi-port lubricant dispenser  10  according the present invention may be tailored to the application in which it is employed. Preferably, the multi-port lubricant dispenser  10  is controlled so as to periodically lubricate each of the lubrication points with which it communicates over a period of several weeks or months. It is also preferred that the electric motor  50  of the electric drive unit  32  be controlled so as to rotate the distributor disk  66  an integral number of rotations at each lubrication interval so that each lubrication point is lubricated the same number of times during each lubrication interval.  
         [0036]    It is to be understood that other configurations of the spindle  36  and the distributor disk  66  that form a floating engagement therebetween besides the one that is described above are also within the contemplation of the present invention. For example, without limitation, the stem  90  of the distributor disk  66  may extend into the motorized lubricant dispenser  12  so that the floating engagement junction is formed in the lubricant reservoir  38  of the motorized lubricant distributor  12  or at or across the junction  16  where the lubricant dispenser  12  is connected to the multi-port distributor  14 . An intermediate section may be used between the spindle  36  and the stem  90  with a floating connection being formed at either or both ends of the intermediate section. Where a stem-less distributor disk is used, the floating engagement junction may be made with the circular plate  88  itself. Furthermore, the receiving cavity need not be slot shaped as shown in FIG. 2 as slot  92 , but may take on any operable shape that provides for rotational drive of the distributor disk  66  by the spindle  36  while permitting some degree of axial direction freedom. Likewise, the insertable element need not be planar shaped as shown in FIG. 2 as planar tip  64 , but may be any shape which is complementary to the receiving cavity employed.  
         [0037]    While preferred embodiments have been shown and described, various modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, the present invention has been described by way of illustration and not limitation. Thus, it is to be distinctly understood that the present invention is not limited thereto, but may be otherwise embodied and practiced within the scope of the following claims.