Abstract:
A cable control assembly is beneficially adapted for shifting controllable mechanisms, such as a power take-off unit, between two conditions, an initial position and an actuated position. The cable control assembly preferably includes a housing, a handle extending from the housing, a driving member, a driven member, and a locking member such as a pawl. Upon shifting of the handle from an initial position to an actuated position, the driving member shifts the driven member, which is operatively coupled to the control cable. Upon reaching the actuated position, the locking member holds the driven member in the actuated position without transmitting a tensioning force applied to the control cable to the driving member. Return of the driving member in a direction toward the initial position automatically causes the locking member to move free of the driven member and enable return of the driven member and control cable to the initial position without other unlocking steps.

Description:
This application claims the benefit of U.S. Provisional Application No. 60/786,854 filed Mar. 29, 2006. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention broadly concerns a cable control apparatus for use in actuating control cables which includes a self locking structure to retain and release a control cable in and from an actuated position in response to handle movement. More particularly, it is concerned with a cable control apparatus for use with a control cable able to retain the control cable in an actuated condition notwithstanding substantial cable tension by virtue of an internal pawl arm acting on a pivoting spool. 
     2. Description of the Prior Art 
     Control cables are widely used in a variety of different applications for remotely controlling mechanisms such as throttles, brakes, chokes and the like. The control cable assembly is often known as a Bowden cable and includes an outer sheath and an internal control cable which is shiftable relative to the sheath. A variety of different controls are well known to those skilled in the art, including those shown and described in U.S. Pat. Nos. 4,363,206, 4,466,232, 4,466,308, 4,813,214, 4,850,182, 5,321,994, 5,467,583, 5,553,822, 5,596,909, 5,657,669, 5,701,967, 5,813,284, and 6,354,170, the disclosures of which are incorporated herein by reference. 
     In some other applications, the force exerted by the mechanism to be controlled has been considered too great, or the length of travel of the controlled mechanism too great to be effective for use with a control cable. For example, in some applications such as a power take-off (PTO) used in a lawn, garden or lightweight utility tractor, a lever with an overcenter retention feature has been used because the tension force exerted by the mechanism was considered too great for the use of a Bowden cable. Some of the considerations in this regard included the force necessary to actuate the lever either to engage or release the mechanism, and the force which must be borne by the control cable assembly in order to successfully retain the control cable and thus the mechanism in an actuated (or released) condition. 
     Accordingly, there has developed a need for an improved control cable apparatus which can effectively actuate, retain and release a control cable under moderate to high levels of tension. 
     SUMMARY OF THE INVENTION 
     It is thus an object of the present invention to provide a control cable assembly which is useful for manual actuation, retention and release of a control cable which is under moderate to high levels of tension, with significant cable travel, particularly in the environment of use of lawn, garden, and light utility tractors. 
     It is another object of the present invention to provide such a self locking control cable apparatus hereof is economical to manufacture and install in a control panel, durable in rugged conditions without requiring significant (if any) maintenance, and presents desirable ergonomic characteristics without extensive machining, a large number of parts, or complicated assembly requirements. 
     It is a further object of the present invention to provide a self locking control cable assembly hereof which retains the cable in an actuated condition with the control cable under tension but without the tension load being borne by a shiftable control handle of the assembly during engagement. 
     It is an additional object of the present invention to provide a self locking cable control apparatus which can be mounted to a control panel or the like and accommodate relatively long cable travel under moderate to high cable tension without necessitating control handles of excessive length which would be incompatible with use on a control panel. 
     In accordance with these and other objects evident from the following description of a preferred embodiment of the invention, a self locking cable control assembly is provided which is particularly useful for mounting to a lawn, garden, or utility tractor to control mechanisms such as a PTO where the mechanism is to be manually actuated by a control cable between an engaged and disengaged condition. The self locking cable control apparatus also avoids then need for excessive manual force to be applied to the handle, or handles of excessive length, given the relatively high tension and long cable travel. The self locking cable control assembly is preferably mounted to the frame, body part, such as a control panel, or other structure of the tractor. By shifting a control handle to from a first position to a second position, the control cable is retained in an engaged position and, correspondingly, the mechanism is engaged. However, the tension force carried by the control cable from the mechanism is borne internally by a pawl within the control assembly once the handle is shifted to the second position, and not transferred to the handle. When the user desires to return the mechanism to a disengaged condition, the handle may be easily shifted back from the second position to the first position, with a pivotal member operatively connected to but separate from the handle serving to release the pawl and thereby permit the cable to shift back under tension to the disengaged condition. Advantageously, this disengagement is effected by a controlled release of the pawl and return of the cable, to inhibit snap movements of the handle and rapid changes in tensioning to the cable during disengagement. 
     The self locking control cable assembly hereof broadly includes a Bowden cable having a sheath and a control cable shiftably movable therewithin, a housing to which one end of the sheath is mounted, a handle mounted for shiftable movement relative to the housing, a driving member connected to the handle for shiftable movement therewith, a driven member operatively connected to the driving member for movement responsive to movement of the driven member, and a pawl mounted for pivotal movement relative to the housing and biased into engagement with both the driving member and the driven member. The control cable is operatively connected to the driven member, whereby pivotal movement of the driven member results in movement of the control cable relative to the housing and the sheath. 
     The driven member is operatively positioned for engagement with the pawl, which is biased by a spring against the driven member. The driven member includes structure, preferably a slot, which receives a post extending from the driving member, whereby the post is permitted limited travel within the slot before it contacts one or another end of the slot. The driven member also preferably includes a circumferentially extending wall. The circumferentially extending wall presents a radially inwardly sloping ramp which ends in a substantially radially extending stop wall. The driving member also preferably includes a circular, circumferentially extending wall having a sloped recess which is oriented rotationally opposite the orientation of the ramp on the driven member, and also includes a radially oriented stop wall at one end. The ramp and the sloped recess are positioned to engage respective parts of the pawl as the driven member and driving member pivot within the housing. In this regard, as the driving member is pivotally moved from an initial position, a peg on the pawl moves radially inwardly along and into the ramp, biased by the spring. This in turn causes a retainer, preferably hook-shaped, on the pawl to hold the driven member, to which the proximate end of the cable is coupled, to hold the driven member and prevent its return when the driving member is in the advanced position. When the driving member is shifted back from the advanced position to the initial position, the driven member gradually moves the peg of the pawl radially outwardly, with the slot permitting relative movement between the driving member and the driven member. When the sloped recess of the driving member moves circumferentially a sufficient distance to cause the peg to move radially outwardly and clear the retainer from the stop wall, the tension on the cable is then able to cause the cable and the driven member to return to the initial position. While in the advanced position, however, the tensioning force on the cable is resisted by the pawl and the stop wall, and is not transferred to the driving member. 
     Thus, the present invention allows a relatively simple, easy to manufacture control assembly which is able to hold a cable in an advanced or engaged position where the tensioning force applied on the cable is relatively great, without transferring the tensioning load to the handle or driving member once shifted to the advanced position. This is advantageously accomplished through a self-locking and unlocking operation, which provides simplicity and permits control operation with only one hand. These and other advantages will be appreciated by those skilled in the art with reference to the drawings and description which follow. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a tractor having an internal combustion engine with a power take-off operatively coupled to the cable control assembly of the present invention; 
         FIG. 2  is a front right side exploded perspective view of the cable control assembly hereof showing the driving member and driven member positioned between the housing halves and the spindle on interior of the left side housing half, with the handle of the driving member in an initial, disengaged position; with the right side housing half removed to show the driving member, driven member, handle and cable of the cable control assembly in an initial position; 
         FIG. 3  is a front left side exploded perspective view of the cable control assembly hereof showing the driving member and driven member positioned between the housing halves and the boss on the interior of the right side housing half with the handle of the driving member in a second, engaged position; 
         FIG. 4  is a fragmentary rear right side perspective view of the cable control assembly hereof with the with the right side housing half removed to show a hook of the pawl riding on the circular outer surface portion of the end wall of the driven member with the handle, driving member and driven member in the initial position; 
         FIG. 5  is an fragmentary rear right side perspective view of the cable control assembly hereof, similar to  FIG. 4 , but showing the handle, driven member, and driving member in the second, engaged position, and the pawl engaging the cable of the cable control assembly in an advanced position with the hook of the pawl holding the driven member; 
         FIG. 6  is an enlarged, left side elevational view of the cable control assembly hereof, with portions of the driving member and driven member shown in phantom lines to illustrate the position of the stub of the driving member within the slot of the driven member and portions of the left housing half removed to show the hook of the pawl in engagement with the stop wall of the driven member when the handle is advanced to the second, engaged position; and 
         FIG. 7  is an enlarged, left side elevational view of the cable control assembly hereof, similar to  FIG. 6 , and showing the follower of the pawl lifting the hook of the pawl free from the stop wall as the handle is moved from the second, engaged position to the initial position. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the drawings, the cable control assembly  10  of the present invention is shown mounted on a vehicle such as a tractor  12 . It is to be understood that the cable control assembly  10  is useful in connection with any other application where a controllable mechanism, such as a power-take-off unit  14  (PTO), is to be shifted between two conditions such as an engaged and a disengaged condition. The PTO  14  as illustrated is shown for operating a mower deck but could be used for other devices such as a snow thrower, rotary tiller, or the like, and the cable control assembly  10  could be used to operate a variety of other mechanisms such as a clutch, blade brake, or any other mechanism having two conditions of operation. Here, the PTO  14  includes a spring or other biasing device which applies a tension force to the remote end  16  of a cable  126  which is typically part of a Bowden cable assembly  20 . 
     The cable control assembly  10  is shown in greater detail in  FIGS. 2 ,  3 ,  4  and  5 , and in the preferred embodiment includes the Bowden cable  20 , a housing  22 , a handle  24  which is connected to or provided as an integral molded assembly with a driving member  26 , a driven member  28 , and a pawl  30 . Preferably, the pawl  30  is biased by a spring  32  against the driving member  26  and the driven member  28  as will be explained in greater detail herein. Threaded fasteners  34  are used to hold the components listed above together as part of the cable control assembly  10 . 
     The housing  22  is preferably provided with first housing half  36  and second housing half  38 , shown in  FIGS. 2 ,  3 ,  4  and  5 . It is to be understood that “half” does not mean exactly ½ of the mass or volume of the housing  22 , but rather that the two halves  36  and  38  are to be mated together in opposing relationship and together provide the housing  22  of the cable control assembly  10  hereof. First housing half  36  includes a first sidewall  40 , a first rim  42 , and an upwardly projecting arcuate first half-dome  44 . The second housing half  38  includes a complementally configured second sidewall  46 , a second rim  48 , and an upwardly projecting arcuate second half-dome  50 . The outer surface  52  of each of the first sidewall  40  and the second sidewall  46  each include one or a plurality of clips  54  integrally molded into the sidewalls for permitting snap-fit insertion and retention of the housing  22  into an opening provided in a control panel of the tractor  12  or other mechanism to be controlled. The first and second rims  42  and  48  together with the clips  54  hold the cable control assembly  10  on a control panel or other supporting surface, with the part of the control panel surrounding the opening into which the cable control assembly  10  is received being held between the clips  54  and the first and second rims  42  and  48 . The first half-dome  44  and the second half-dome  50  include arcuate guide rims  56  and  58  which help to retain and guide the driving member  26  during shifting, and also help to substantially enclose the cable control assembly  10  against the intrusion of dirt and other debris. 
     The first sidewall  40  of the first housing half  36  has an first inside surface  60  which is best seen in  FIG. 3 . The first inside surface  60  includes a pair of receivers  62  which receive threaded fasteners  34  such as self-threading bolts  64 , a bearing  66  for pivotally mounting the pawl  30 , and a circular boss  68  which projects inwardly into the cable control assembly  10  and has a central hole  70  for receiving a bolt  72  or other fastener therethrough. The second sidewall  46  of the second housing half  38  includes a second inside surface  74  which is best seen in  FIG. 2 . The second inside surface  74  includes a pair of tubular passages  76  for receiving the bolts  64 , the tubular passages  76  being aligned with the receivers  62  when the housing halves  36  and  38  are mated. The second inside surface  74  further includes a bearing  77  for pivotally mounting the pawl  30 , a spindle  78  for pivotally mounting the driving member  26 , and an arcuate inwardly projecting wall  80  which encloses and defines therein an arcuate-shaped sector  82 . The sector  82  extends in an arcuate direction and is bounded by the wall  80  to define the limit of travel of the driving member  26  through its desired range of motion, typically about 30 degrees to about 80 degrees. The spindle  78  is substantially cylindrical but with a slight taper for purposes of molding, has a central hole  83  for receiving a threaded fastener therethrough, and is complementally configured to pivotally mount the driving member  26  thereon. 
     The handle  24  is preferably molded so as to be unitary with the driving member  26 , and has an elongated shank  84  and a grip  86  extending angularly to the shank  84 . The elongated shank  84  provides a significant lever arm to move the control cable  126  of the Bowden cable  20 , which is maintained under tension. 
     The driving member  26  is preferably integrally molded as a unitary member with the handle  24  and includes an end wall  90  which is, at least in part, substantially circular, a sidewall  92  having a first side  94  and a second side  96 , and a hub  98  which is sized for pivotal movement about the spindle  78 . A plurality of gussets  100  are arranged in a spoke-type pattern, extend radially along and connected with the first side  94  of the sidewall  92 , and also extend between and are connected to the end wall  90  and the hub  98  as shown in  FIG. 3 . One of the gussets  100  preferably has a substantially cylindrical lug  102  extending toward the sector  82  when mounted onto the spindle  78  whereby the lug is complementally shaped with the inwardly projecting wall  80  for travel within the wall  80  through the sector  82 . Thus, the wall  80  both helps to maintain integrity and alignment of the cable control assembly  10  hereof, and to limit the pivotal movement of the driving member  26  because of engagement with the wall  80  at the limit of the travel of the lug  102 . The sidewall  92  also includes a stub  104  which extends from the second side  96  and opposite the lug  102 . Thus, the stub  104 , which is preferably substantially cylindrical, thus extends in a direction toward the driven member  28  when the cable control assembly  10  hereof is assembled. The preferably circular circumferentially extending end wall  90  also includes a radially inwardly sloping recess  106  which ends in a radially extending stop wall  108 . The recess  106  occupies only a portion of the end wall  90 , with the remainder of the end wall  90  being substantially equidistant from the hub  98 . The stop wall  108  is preferably at the end of the recess  106  proximal to the handle  24 , and thus slopes upwardly away from the hub  98  as it extends circumferentially distal from the stop wall  108  and the handle to the ramp beginning  106 . 
     The driven member  28  is substantially disc-shaped and includes a central bearing  110 , a sidewall  112  having a first side  114  and a second side  116 , and an end wall  118  which includes a portion which is preferably substantially circular. The sidewall  112  includes a slot  120  which is elongated and arcuate in its circumferential direction and sized to receive the stub  104  of the driving member  26  therein. The sidewall also includes a transverse hole  122  for receiving a terminal  124  which is positioned at a proximate end of a control cable  126  of the Bowden cable  20 . The end wall  118  includes a circumferentially extending slit  128  therein for receipt of the portion of the control cable  126  which is immediately adjacent the terminal  124  as the driven member  28  pivots, the slit  128  also serving as a guide for the control cable  126 . The end wall  118  further includes, on a portion thereof which is preferably relatively remote from the slot  120 , a radially inwardly sloping ramp  130  which ends in a substantially radially extending stop wall  132 . as can be seen in  FIGS. 2 and 3 , the ramp  130  slopes in an opposite direction relative to the pivoting or circumferential movement of the recess  106  of the driving member  26 . Thus, the stop wall  132  is, with respect to the circumferential or pivoting movements of the driving member  26  and the driven member  28 , in facing relationship to the stop wall  108  of the recess  106 . 
     The pawl  30  includes an elongated pawl arm  134  and a pivot shaft  136  which is oriented transverse to the longitudinal axis of the pawl arm  134 . The pivot shaft  136 , seen in  FIGS. 3 and 4 , is sized for receipt within the bearings  66  and  77  of the housing halves. The pivot shaft  136  is located at one end of the pawl arm  134 , and a hook  138  is located at the opposite end of the pawl arm  134 . The hook  138  extends radially inwardly and is sized for receipt by the ramp  130  of the driven member  28 . A follower  140  is positioned on the pawl arm  134  adajacent the hook  138 . The follower  140  is preferably substantially parallel to the axis of the pivot shaft  136  and relatively remote therefrom. The follower is oriented toward the driving member  26  and sized to ride along the end wall  90  until aligned with the recess  106  into which it is received when the cable control assembly  10  is assembled. The biasing spring  32  is mounted on the pawl  30  proximate the pivot shaft  136  with respective ends of the spring  32  engaging the housing and the pawl  30  to bias the hook  138  radially inwardly. 
     The Bowden cable  20  hereof includes the control cable  126  having the terminal  124  at the end proximate the housing  22  and a remote end operatively connected to the power take-off unit  14  or other controllable mechanism, and a sheath  142  as is conventional. The control cable  126  slides within the sheath  142 , which is maintained against translational movement relative to the housing by fitting  144 , which is received by receptacles  146  and  148  of the respective housing halves  36  and  38 . The sheath  142  then leads through an opening  150  in one of the housing halves as shown, for example, in  FIG. 3 . 
     The control cable assembly  10  is assembled as illustrated in the drawing figures, with the terminal  124  connected to the driven member  28 , the fitting  144  placed in one of the receoptacles  146  or  148 , and the driving member  26  mounted on the spindle  78 . Further, the pawl  30  is mounted with the spring  32  thereon and the shaft  136  received in the bearings  66  and  77 , the lug  102  positioned within the sector  82 , and the stub  104  within the slot  120 . The two housing halves  36  and  38  are mated together, and the threaded fasteners  34  used to secure the housing halves. 
     In use, the handle  24  and thus the driving member  26  begin in an initial position shown in  FIG. 4 . In this position, the stub  104  is positioned at the circumferentially forward end  152  of the slot  120 , such that as the handle  24  is moved forwardly toward the position shown in  FIGS. 5 and 6 , the driven member  28  pivots with the driving member  26 . As the driving member  26  and driven member  28  pivot together about the axis defined by the spindle  78 , the proximate end of the control cable  126  is received into the slit  128  and the retraction of the control cable  126  into the housing  22  begins to actuate the PTO  14  or other controllable mechanism. As viewed in  FIG. 6 , the forward movement of the handle causes both the driving member  26  and the driven member  28  to pivot in a clockwise direction. As the driven member  26  moves clockwise, the recess  106  of the driving member is no longer engaged by the follower  140 , which frees the hook  138  to move radially inwardly, biased by the spring  32 , once the driven member  28  moves a sufficient amount in the clockwise direction. The stub  104  continues to engage the sidewall adjacent the slot  120  until the hook  138  clears the stop wall  132 . At that point, the hook  138  drops into the ramp  130 . The handle  24  may then be released by the operator, and the tension applied to the control cable  126  actually aids in maintaining the hook  138  against the stop wall  132  to prevent counterclockwise movement of the driven member  28  which would, in turn, cause the unloading movement of the control cable in a remote direction. In this way, the tensioning force applied via the control cable  126  is borne by the action of the hook  138  on the driven member  28 , and not transmitted to the driving member  26  or handle  24 . Thus, notwithstanding the tension applied by the controllable mechanism  14  on the control cable  126  and the release of the handle  24  by the operator, the driven member  28  and thus the control cable  126  remains in its forward, engaged position as illustrated in  FIG. 6 . The stop wall  108  may also help, together with the other features herein listed, excess forward or clockwise movement of the driving member  26 . 
     When the operator desires to disengage the PTO  14 , the only movement necessary is movement of the handle  24  rearwardly as illustrated in  FIG. 7 . During the movement of the handle rearwardly, and thus the counterclockwise movement of the driving member  26  as illustrated in  FIG. 7 , the circumferential extension of the slot  120  permits the stub  104  to move counterclockwise a desired distance before engaging the rearward end  154  of the slot  120 . Thus, the driving member  26  is permitted limited counterclockwise pivoting movement relative to the driven member  28  which remains pivotably stationary, held in place by the hook  138 . As the driving member  26  moves in a counterclockwise direction as illustrated in  FIG. 7 , follower  140  begins to ride along the sloping recess  106  and move radially outwardly relative to the axis or spindle  78 . The follower  140  continues this radially outward movement until the follower  140  substantially moves out of the recess and thus onto the other portion of the end wall  118  which is here shown as substantially circular. This radially outward movement of the follower  140  causes the pawl  30  to pivot and the hook  138  to clear the stop wall  132 . When the hook  138  clears the stop wall  132 , the hook  138  no longer prevents counterclockwise movement of the driven member  28 , which is now free to return to the initial position shown in  FIG. 4 , either as a result of the continued movement of the handle  24  rearwardly which in turn moves the driving member  26  with its stub  104  against the rearward end  154  of the slot  120 , or as a result of tension applied to the control cable  126  and transferred through the driven member  28  to the driving member  26  and handle  24 . As the driven member  28  moves counterclockwise, the control cable unloads and shifts relative to the sheath to permit the PTO  14  or other controllable mechanism to disengage. 
     Although preferred forms of the invention have been described above, it is to be recognized that such disclosure is by way of illustration only, and should not be utilized in a limiting sense in interpreting the scope of the present invention. Obvious modifications to the exemplary embodiments, as hereinabove set forth, could be readily made by those skilled in the art without departing from the spirit of the present invention. For example, the end walls of the driving member and driven member need not be substantially circular, but rather only a sector of an arcuate configuration may be provided. Also, the action of the control cable on the controllable mechanism may readily be a negative one, such that in the initial position, the controllable mechanism is engaged, and when the driving member is shifted clockwise, the controllable member disengaged. Of course, all descriptions of forward, rearward, clockwise and counterclockwise are provided to assist the reader in the understanding of the orientation as illustrated, and may be changed depending on the particular application and orientation of the cable control assembly in use. 
     The inventor hereby states his intent to rely on the Doctrine of Equivalents to determine and assess the reasonably fair scope of his invention as pertains to any apparatus not materially departing from but outside the literal scope of the invention as set out in the following claims.