Abstract:
A cable guide for improving performance and longevity of a dispenser actuator for remotely operating a dispensing unit with a flexible cable connected between a valve of the dispensing unit and the actuator. The cable opens or closes the valve by manipulating the actuator adjacent the discharge end of the tube. The guide is positioned within the actuator in physical contact with the cable. The guide may comprise a thin arched body extending upward from a leading edge to a peak and downward to a trailing edge. The cable can slide over the guide as the actuator operates the valve. The guide prevents the cable from bending with a small bend radius, e.g., smaller than five or ten or even twenty times a diameter of the cable as the actuator operates the valve.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application claims priority to U.S. Provisional Patent Application Ser. No. 62/267,320, filed Dec. 15, 2015. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention is in the technical field of cable guides. More particularly, the present invention is in the technical field of liquid dispenser actuators employing said cable guides. 
         [0003]    Certain lever-actuated mechanisms make use of flexible, elongated cables to transfer the point of application of a mechanical force from the actuated lever to a remote location. For example, some hand actuated brake or shifter levers on bicycles and motor bikes take advantage of this transfer of mechanical force to permit riders to apply brakes or shift gears at different parts of the cycle by actuating the levers on the handlebars. Another example of a hand actuator that uses a flexible cable to transfer mechanical force is a liquid dispenser of the type disclosed in U.S. Pat. Nos. 6,299,035 and 7,516,763, the disclosures of which are expressly incorporated by reference herein. 
         [0004]    Ideally, flexible cable actuators are designed so that the motion of the cable is largely linear or without significant bends. That is, as the lever actuator is actuated to pull the flexible cable, the cable should be pulled out of its ferrule or housing in generally the same direction as the cable is oriented prior to actuating the lever. Keeping the cable straight and avoiding sharp bends during actuation can improve product longevity, avoiding kinks in the cable to maintain optimal performance, and to reduce the likelihood that the cable will break or fray with continued use. 
         [0005]    Unfortunately, design or material constraints may force designers to mount the flexible cable in suboptimal arrangements. For example, in the Prior Art embodiments illustrated in  FIGS. 5A-5B , a flexible cable  110  is used in the exemplary actuator  100  to selectively control the flow of liquid from a remote dispensing unit  120 . The Prior Art actuator  100  is attached towards a discharge end of a dispensing tube  112 , through which a mixture of water and cleaning chemical is dispensed. The appropriate mixture of water and cleaning chemical is provided by the dispensing unit  120  through the use of known proportioning systems such as eductors, aspirators or proportioners. A water shutoff valve  122  is connected to the dispensing unit  120  to control the flow of liquid through the inlet of dispensing tube  112 . In order to control the shutoff valve  122  from the discharge end of the dispensing tube  112 , the actuator  100  makes use of a flexible cable  110  that is coupled between the actuator  100  and the shutoff valve  122 . 
         [0006]    The actuator  100  includes a pivotally attached lever  114  that triggers the flow of liquid through the dispensing tube  112 . The flexible cable  110  includes a ferrule or housing  116  that is secured to an upstream portion of actuator  100 . Meanwhile, the downstream end of flexible cable  110  is secured to the lever  114  such that whenever the lever  114  is actuated between the non-dispensing condition in  FIG. 5A  and the dispensing condition in  FIG. 5B , the flexible cable  110  is pulled through the housing  116  and moves the valve  112  in the dispensing unit  120  into an open, flowing position. 
         [0007]    Unfortunately, with exemplary Prior Art actuators  100  of the type shown in  FIGS. 5A-5B , actuating the lever  114  ( FIG. 5B ) to start the flow of liquid through dispensing tube  112  forces the flexible cable  110  to bend at an extreme angle α relative to its original, non-dispensing position ( FIG. 5A ). Bending over such an extreme angle α does not in itself pose a fatigue problem for the flexible cable  110  as long as the cable  110  is bent over a sufficiently large bend radius. A good rule of thumb for bending steel cable is that the bend radius should be kept to larger than 10 times the cable diameter and preferably over 20 times the cable diameter. In the present example, however, the flexible cable  110  is bent over a hard, sharp edge of the actuator  100  as it extends to the dispensing position ( FIG. 5B ). In the Prior Art actuator  100 , the flexible cable  110  is bent over a small bend radius that is really only on the order of a few cable diameters large. Repeated actuations, and hence repeated over-bending and over-flexing of the flexible cable  110  will ultimately lead to premature fraying, breaking, and failure of the flexible cable  110  and the actuator  100 . Water regulatory agencies may require a certain number of actuations before failing. Furthermore, the default failsafe mode should be that the water valve shuts in the event of any failure. However, with the Prior Art actuators, the frayed cable often gets stuck and does not retract completely into the cable housing  116 , thereby leaving the water valve  112  open. Therefore, there is a need in the industry for a solution that mitigates the problem of flexible cable failures present in exemplary Prior Art actuators  100  of the type shown in  FIGS. 5A-5B . 
       SUMMARY OF THE INVENTION 
       [0008]    One or more embodiments of the present invention relate to a guide for flexible cables used in liquid dispensing actuators comprising a thin arched body extending upward from a leading edge to a peak and downward to a trailing edge, a planar ramped section extending from the leading edge towards the peak of the arched body, an arcuate deflecting section extending from the end of the planar ramped section and terminating at the trailing edge, and a recessed cable channel forming a trench protruding below the planar ramped section in a direction opposite the peak, the cable channel beginning at the leading edge and extending towards but terminating before the trailing edge. In one embodiment, the thin arched body is fabricated from sheet metal. 
         [0009]    Another aspect of the present invention relates to a dispenser actuator for remotely operating a dispensing unit having a proportioner for combining and dispensing a plurality of liquids in a selected proportion and a valve for passing and cutting off at least one of said liquids, the actuator comprising a dispensing tube having an inlet end and a discharge end, said tube adapted to be in liquid communication with the dispensing unit at the inlet end of the dispensing tube, an actuator disposed adjacent the discharge end of said dispensing tube, a flexible elongated member operably connected between the valve of the dispensing unit and the actuator such that the valve is opened and closed by manipulating the actuator adjacent the discharge end of the tube, and a guide for controlling a path of travel of the flexible elongated member as the actuator is manipulated to operate the valve in the dispensing unit. In one embodiment, the guide is positioned within the actuator in physical contact with the flexible elongated member. In one embodiment, the guide may comprise a thin arched body extending upward from a leading edge to a peak and downward to a trailing edge, a ramped section extending from the leading edge towards the peak of the arched body and a deflecting section extending from the end of the ramped section and terminating downward at the trailing edge. The flexible elongated member can slide over the deflecting section of the guide as the actuator is manipulated to operate the valve in the dispensing unit. In one or more embodiments, the guide prevents the flexible elongated member from bending with a small bend radius as the actuator is manipulated to operate the valve in the dispensing unit. In one or more embodiments, the guide prevents the flexible elongated member from bending with a bend radius smaller than five or ten or even twenty times a diameter of the flexible elongated member as the actuator is manipulated to operate the valve in the dispensing unit. 
         [0010]    Embodiments of the cable guide disclosed herein may be used to retrofit dispenser actuators for remotely operating a dispensing unit having a proportioner for combining and dispensing a plurality of liquids in a selected proportion and a valve for passing and cutting off at least one of said liquids. The retrofitting method may comprise detaching a flexible elongated member operably connected between the valve of the dispensing unit from a lever of the actuator. In such systems, the flexible elongated member is configured to open and close the valve by manipulating the lever of the actuator adjacent the discharge end of the tube. After detaching the flexible elongated member from the lever, the retrofitting process continues by inserting an arched guide for controlling a path of travel of the flexible elongated member as the actuator is manipulated to operate the valve in the dispensing unit. Inserting the guide comprises positioning a leading end of the guide under the detached flexible elongated member and elastically deforming a trailing end of the guide to positively engage the trailing end of the guide within an opening in the dispenser actuator. Then, the retrofitting is continued by routing the flexible elongated member over a peak of the arched guide and re-attaching the flexible elongated member to the lever of the actuator. Once inserted, the cable guide is capable of preventing the flexible elongated member from bending with a small bend radius, such as five or ten or twenty times a diameter of the flexible elongated member while manipulating the lever of the actuator to operate the valve in the dispensing unit. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         [0011]      FIG. 1  is a perspective view of an embodiment of a cable guide of the present invention; 
           [0012]      FIG. 2A  is a top view of the cable guide of  FIG. 1  prior to forming into a final shape; 
           [0013]      FIG. 2B  is an end view of the cable guide of  FIG. 1  prior to forming into a final shape; 
           [0014]      FIG. 3  is a side view of the cable guide of  FIG. 1 ; 
           [0015]      FIG. 4A  is a side cutaway view of an embodiment of a cable guide of the present invention installed in a representative liquid dispenser actuator in a non-dispensing state; 
           [0016]      FIG. 4B  is a side cutaway view of an embodiment of a cable guide of the present invention installed in a representative liquid dispenser actuator in a dispensing state; 
           [0017]      FIG. 4C  is a side perspective cutaway detail of an embodiment of a cable guide of the present invention installed in a representative liquid dispenser actuator; 
           [0018]      FIG. 5A  is a side cutaway view of a Prior Art liquid dispenser actuator in a non-dispensing state; 
           [0019]      FIG. 5B  is a side cutaway view of a Prior Art liquid dispenser actuator in a dispensing state; and 
           [0020]      FIG. 6  lists retrofit method steps for implementing a cable guide within a representative liquid dispenser actuator according to an embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0021]    Referring now to the invention in more detail,  FIGS. 1-3  show an exemplary cable guide  10  in various stages of manufacture for use within a liquid dispenser actuator  50  as shown in  FIGS. 4A-4C . In the illustrated embodiment, the cable guide  10  includes a generally flattened, elongated construction. In one embodiment, the cable guide  10  may be formed from sheet metal, including for example, stainless steel. The stainless steel may be heat treated steel using known methods such as tempered or annealed. The tempered stainless steel may be selected from a variety of known compositions, including for example 201; 301, 304; or 410 stainless. The sheet metal may be a spring steel. Further, the sheet metal may be hardened to various hardnesses as are known, including for example ¼ hard, ½ hard, or full hard. The cable guide  10  may be constructed of other metals, including for example hardened or anodized aluminum or titanium. 
         [0022]    In various embodiments, the cable guide  10  may be constructed from sheet metal having a thickness between about 0.2-0.4 mm, although thicker or thinner cable guides are also contemplated. As seen in  FIG. 2A , the cable guide is generally formed from an elongated, rectangular blank  12  with a length L that is several times larger than the width W. In one embodiment, the length L of the rectangular blank  12  is about 55-60 mm long and the width W of the blank  12  is about 12-16 mm wide. In one embodiment of the blank  12 , the length is 58 mm, the width is 14 mm, and the thickness is 0.3 mm. 
         [0023]    Referring still to  FIG. 2A , the illustrated embodiment of the cable guide  10  may be created from a rectangular blank  12  that is further processed to create a desired final shape that is non-flat. In the illustrated example shown specifically in  FIGS. 1&amp;3 , the cable guide  10  is characterized by a generally arched shape, that begins at a leading end  18  with a substantially planar ramp section  24  and continues to a curved deflecting section  26  and terminates at a trailing end  20 . The generally arched shape, and particularly the curved deflecting section  26  assist in changing the path along which the flexible cable  110  travels as it extends and retracts between the dispensing and non-dispensing positions shown in  FIGS. 4A and 4B . The ramp section  24  extends a distance M from the leading end  18  towards the curved deflecting section  26 . The distance M may be between about 25-30 mm. The curved deflecting section  26  has a radius of curvature R that is sufficient to increase the bend radius of the flexible cable  110  as it extends and retracts between the dispensing and non-dispensing positions shown in  FIGS. 4A and 4B . The radius of curvature R of the deflection section  26  may be between about 20-25 mm. This radius of curvature may R be altered as space within the dispenser actuator  50  might permit, but it is certainly desirable to make the dimension R larger than five or perhaps even eight times the diameter of the flexible cable  52 . In some embodiments, the radius of curvature R is larger than 10 times the diameter of the flexible cable, which may be between 1-2 mm. In one embodiment, the ramp section  24  extends a distance M of about 27 min from the leading end  18  of the cable guide  10  and the radius of curvature R of the deflecting section  26  is about 22 mm. 
         [0024]    At a leading end  18  of the blank  12 , a guide channel  14  is created by a stamping, pressing, or forming process. The guide channel  14  is a recessed valley or trench region below the surface of the ramp section  24  at the leading end  18  of the cable guide  10  that provides clearance for the cable housing  116  (see e.g.,  FIG. 5A ) or any related hardware securing the cable housing  116  to the dispenser actuator  50 . In the illustrated embodiment, the guide channel  14  is formed with a generally curved, arcuate cross section (see  FIG. 2B ). In this embodiment, the guide channel  14  is formed to a depth D that is between about 1-2 mm. The arcuate cross section of the guide channel follows a generally circular shape with a diameter G of between 5-9 mm. In one embodiment, the depth D is about 1.5 mm and the diameter G is about 7 mm. The depth and size of the guide channel  14  should be large enough to prevent interference with the cable housing  116  or any related hardware. Any interference that may exist because of the absence or improper sizing of the guide channel  14  may hinder the motion of the flexible cable  110  (see  FIG. 4A-4B ) as the flexible cable  110  extends and retracts between the dispensing and non-dispensing positions. The guide channel  14  may extend a sufficient distance V from the leading end  18  of the cable guide  10  to provide the aforementioned clearance for the housing  116  or related hardware. Depending on the type of housing  116  or hardware used, this channel distance V may be between about 5-10 mm. In one embodiment, this distance V is about 7 mm. Located at the end of this distance V from the leading end  18  of the cable guide  10  is a transition region  16 , where the guide channel  14  ends and transitions from the recessed shape to a substantially planar shape exhibited by the ramp section  24  and the rest of the cable guide  10 . 
         [0025]    At the trailing end  20  of the cable guide  10  are optional two chamfers  22  that improve the fit of the cable guide  10  within the dispenser actuator  50 . The chamfers  22  are cut or ground to remove material at an angle A from the trailing end  20  and at a distance C from the sides  28 ,  30  of the cable guide  10 . In one embodiment, the angle A is about 30 degrees and the distance C is about 4 mm. In the illustrated embodiment, the chamfers  22  remove roughly one third of the trailing end  20  of the cable guide so that only the central portion of the trailing end  20  between the chamfers  22  contacts the interior of the dispenser actuator  50  as shown in  FIG. 4C . As indicated above, the chamfers  22  may be included to improve fit, but may be omitted to decrease part cost and complexity if a particular implementation permits. 
         [0026]      FIG. 4C  shows a rotated isometric cutaway detail view of the cavity  52  in the dispenser actuator  50  in which the cable guide  10  is placed. The flexible cable  110  is omitted from  FIG. 4C  for clarity. In  FIG. 4C , one can see that the guide channel  14  provides the aforementioned clearance for the cable housing  116 . At the opposite end of the cable guide  10 , the portion of the trailing end  20  between the chamfers  22  abuts two cable blocks  54  on the dispenser actuator  50 . In order to install the cable guide  10  into the cavity  52 , a retrofit process  600  such as that shown in  FIG. 6  may be used. In a first step  602 , the flexible cable  110  may be detached from the lever  114 . In a second step  604 , the cable guide  10 , particularly the leading end  18  is inserted over the cable blocks  54 , under the flexible cable  110 , and under the cable housing  116 . As indicated at step  606 , inserting the cable guide  10  in this manner may require elastic deformation of the cable guide  10  (i.e., bending of the trailing end  20  up and over the cable blocks  54 ) so material choice is indeed an important consideration. Therefore, a ductile material such as spring steel may be desirable. Lastly, at step  608 , the flexible cable  110  is re-routed over the cable guide  10  and re-attached to the actuator lever  114 . 
         [0027]    In both the Prior Art actuator  100  and the improved actuator  50 , the flexible cable  110  passes between these two cable blocks  54  to connect with lever  114 . In the Prior Art dispenser  100 , the flexible cable slides and bends over edge  56  as the lever  114  moves between the dispensing and non-dispensing positions. However, with the cable guide  10  positioned within the improved dispenser actuator  50 , the flexible cable  110  is redirected up and away from edge  56  so that it avoids contact with or makes very light contact with the edge  56 . Moreover, the cable guide prevents the flexible cable  110  from bending over the edge  56  and greatly increased the bend radius of the flexible cable  110  as the lever  114  moves between the dispensing and non-dispensing positions. 
         [0028]    In the improved configuration of the dispenser actuator  50  that includes a cable guide  10 , the flexible cable  110  may still pass between the cable blocks  54 . Thus, the cable blocks  54  help to keep the flexible cable  110  properly positioned and prevent excess lateral displacement of the flexible cable  110 . To the extent possible, extraneous motion of the flexible cable  110  should be controlled to ensure long term repeatable performance. To that end, in an alternative embodiment, a slightly modified cable guide channel  14 A may extend a further distance from the leading end  18  of the cable guide  10 , and terminating at a transition region  16 A that is closer to the trailing end  20 . In one embodiment, the guide channel  14 A extends beyond a midline  58  of the cable guide  10  so that transition region  16 A is closer to the trailing end  20  than it is to the leading end  18 . In another embodiment, the guide channel  14 A extends beyond a midline  58  of the cable guide  10  so that transition region  16 A is located near, at, or beyond a peak  60  of the deflecting section  26 . By extending the cable guide  14 A in this manner, the flexible cable  110  may be constrained to stay within the cable guide  14 A to provide additional control over unwanted lateral motion of the flexible cable  110  as the lever  114  moves between the dispensing and non-dispensing positions. 
         [0029]    In an alternative embodiment, because lateral motion of the flexible cable  110  is constrained by cable blocks  54  or other external features, the cable guide  10  may be manufactured without any guide channel  14 ,  14 A at all. Assuming that the cable guide can be inserted without causing any unnecessary binding or contact with other parts, including the ferrule or cable housing  116 , then part costs may be reduced by eliminating the guide channel  14 ,  14 A. 
         [0030]    While the foregoing written description of the invention enables one of ordinary skill to make and use what is considered presently to be the best mode thereof, those of ordinary skill will understand and appreciate the existence of variations, combinations, and equivalents of the specific embodiment, method, and examples herein. The invention should therefore not be limited by the above described embodiment, method, and examples, but by all embodiments and methods within the scope and spirit of the invention as claimed. 
         [0031]    For example, embodiments of the cable guide presented above have been described in the form of a thin sheet metal component. In alternative embodiments, the cable guide may be integrated as a feature molded within the internal stricture of the actuator. Thus, the cable guide may be molded, for example by injection molding, as a part of the actuator body. Alternatively, the cable guide may be made of materials other than sheet metal. The cable guide may be manufactured using a molding process of plastic materials such as, but not limited to PTFE, POM, Acetals, ABS, PVC, Polypropylene, or Polyethylene. Such plastics may be used as is or may be modified to include abrasion resistant coatings that can be applied with known application methods, including but not limited to spray, dip, deposition or other methods.