Patent Publication Number: US-2011072933-A1

Title: Lever lockout assembly

Description:
FIELD OF THE INVENTION 
     The present invention relates to a lever lockout assembly. 
     BACKGROUND OF THE INVENTION 
     Tractors and other utility vehicles are typically equipped with control levers which control the operation of devices, such as selective control valves (SCV). In many markets regulations require mechanisms which can secure such levers in a neutral position, such as when the vehicle is in transport or when the SCV is not being used. Such a mechanism can prevent activation of the SCV as a result of accidental contact with the lever or as a result of vibration. 
     Some SCV lever lockout mechanisms have included sliding lockout members, and the sliding motion can be hindered by friction and contamination. It is desired to have a lockout mechanism which has a lockout member which pivots instead of sliding. 
     SUMMARY OF THE INVENTION 
     Accordingly, an object of this invention is to provide a lever lockout assembly which includes a pivoting lockout member. 
     This and other objects are achieved by the present invention, wherein a lever lockout assembly includes a housing, a lever support mounted on the housing, a lockout support mounted on the housing, a lever member, and lockout member pivotally supported by the lockout support. The lever member has a pivot plate and a lip projecting from the pivot plate. The pivot plate is rotatably supported by the lever support, and the pivot plate has notch formed in an outer surface thereof. The lockout member is pivotal to a lockout position wherein the lip is received by the notch, and to an unlocked position wherein the lip is outside of the notch and the pivot plate is rotatable. A lockout spring member projects from the lockout member and extends through a U-shaped slot in a cover of the housing. 
     The lockout slot is a U-shaped slot having a main slot and first and second end slots extending transversely with respect to the main slot. The lockout spring member is biased to engage an end of the first end slot when the lockout member is in the unlocked position, and is biased to engage an end of the second end slot when the lockout member is in the locked position. The lockout member has a substantially L-shaped cross sectional shape. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a top perspective view of a vehicle control console including the present invention; 
         FIG. 2  is a top perspective of the control console of  FIG. 1  with the cover removed showing the lockout member in a locked position; 
         FIG. 3  is a perspective view of the control console of  FIG. 2  showing the lockout member in an unlocked position; 
         FIG. 4  is a enlarged detailed side view showing the slot in the base of one of the levers of  FIG. 2 . 
         FIG. 5  is a partially sectional perspective view of the lever lockout mechanism showing how the lockout member is pivotal supported by the housing; 
         FIG. 6  is a perspective view of the lockout member of  FIGS. 1-5 ; 
         FIG. 7  is a perspective showing the housing lockout slot and showing the spring arm in an unlocked position; and 
         FIG. 8  is a perspective showing the housing lockout slot and showing the spring arm in a locked position. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to  FIGS. 1-3 , a control console  10 , for a vehicle (not shown) such as an agricultural tractor or utility vehicle, includes a housing  12  with an upper cover  16  and a lower cover  17 . The cover  16  has a plurality of lever slots  18  through which project control levers  20 . A lower part  22  of each control lever  20  is preferably pivotal on a pivot pin  24  and is coupled to a conventional linkage  26  (see  FIG. 2 ), which is in turn, operatively coupled to a controlled device, such as a conventional selective control valve (not shown). The cover  16  also has a U-shaped slot  30  though which extends a spring arm  32  for manipulation by an operator. A lockout member  14 , preferably made out of steel, is pivotally supported in the housing  12  adjacent the levers  20 . 
     As best seen in  FIGS. 2 and 3 , the ends of pivot pin  24  are supported by a pair of support blocks  34 ,  36  which are formed by the housing  12 . A lever lockout slot  38  is formed in the lower part or base  22  of each lever  20 . In  FIG. 2 , the lockout member is shown in its lockout position wherein a portion of the lockout member  14  is received by the slots  38 . In  FIG. 3 , the lockout member  14  is shown in its unlocked position wherein a portion of the lockout member  14  is withdrawn from the slots  38 . 
     As best seen in  FIG. 4 , each slot  38  is preferably centered on a plane P which contains the pivot axis of pivot pin  24 . Each slot  38  has an upwardly slanted upper lip  44 , and a downwardly slanted lower lip  46 . Each lip  44  and  46  is preferably tilted by 15 degrees with respect to the plane P, so that the mouth of each slot  38  is wider at its outer end. This wider mouth enhances the ease of alignment of each individual lever slot  38  with the lockout member  14  as it is rotated to the lock position. The width of the slots has some clearance with respect to the thickness of the lockout member  14  to ensure that the lockout member  14  can be inserted into and removed from the slots  38 . This clearance should preferably be set small enough to prevent the lever  20  from rotating enough to actuate the valve (not shown) to which it is operatively connected. 
     As best seen in  FIGS. 5 and 6 , the lockout member  14  has a pair of end walls  50  and  52  attached to opposite ends of lockout plate  54 . Plate  54  has an upside down L-shaped cross sectional shape, and has a main part  55  and a lip  56  which is bent and extends generally perpendicularly at an upper end of main part  55 . The lip  56  is the part of the lockout member  14  which is received by the slots  38 . Pivot pins  58  and  60  project outwardly from a lower portion of the end walls  50  and  52 , respectively. The pivot pins  58 ,  60  are preferably screws or bolts which are inserted through threaded holes in the end walls  50 ,  52 , and into pivot bores  62 ,  64  formed in a lower part of housing  12 . 
     As best seen in  FIG. 6 , the spring arm  32  has a lower end  70  which engages the end wall  52  and an end of plate  54 . The lower end  70  may be brazed or welded to the end wall  52 . Spring arm  32  passes through an aperture  74  formed between the lip  56  and the upper end of end wall  52 . A loop at the top of spring arm  32  forms a handle  76 . 
     As best seen in  FIGS. 7 and 8 , the spring arm slot  30  has a “U” shape with a main slot portion  78 , a first or unlocked end slot  80  and a second or locked end slot  82 . The spring arm  32  passes through the U-shaped slot  30  in the upper cover  16 . When the lockout member  14  is in its unlocked position, spring arm  32  will be received in first end slot  80 . When the lockout member  14  is in its lockout position, spring arm  32  will be received in second end slot  82 . Spring arm is biased so that it is urged against the ends of ends slots  80  and  82  when it is released by an operator. 
     The operator can flex the spring arm  32  to the left viewing  FIGS. 7 and 8 , to move the spring arm  32  into the main slot portion  78  so that the spring arm  32  can be moved between the locked and unlocked positions. To move the locking member  14  to the “locked” position, the operator flexes the spring arm  32  into the slot  78  ad then into end slot  82 . This rotates the locking member  14  so that lip  56  is received by the notches  40  in the levers  20 , thus locking them in a neutral position and preventing oil flow through the valves (not shown) coupled thereto. The spring arm  32  is biased slightly to both the locked and unlocked positions by its engagement with the wall  56  and the aperture  74 . This prevents the locking member  14  from rattling due to vibrations inherent in the operation of an agricultural vehicle. This lever lockout assembly can be used on a tractor with one or multiple control levers. 
     The upper cover  16  receives loads for the flexing of the spring arm  32 . The load from the operator inadvertently trying to move a lever  20  with the lock engaged would be transferred through the locking member assembly to the lower cover  17  through the pivot pins  58  and  60 . The lower cover  17  is preferably made out of a structural plastic designed to take the loads placed on the levers  20 . 
     This lockout assembly meets the selective control valve lockout homologation requirements in various countries, and enables an operator to lock or unlock all of the SCV levers in a console. It accomplishes this with a rotating locking member assembly with a few parts. After the cables are assembled to the valves and control levers  20 , the levers  20  can be locked to the neutral position. The cable length for each control can be adjusted to the proper length for the neutral position of the valve. After the adjustments are completed, a cable end locking clip (not shown) is installed. This reduces the number of adjustment iterations required during initial assembly or service. This new design uses a robust pivoting locking member that is capable of withstanding the loads an operator may put into the system. 
     While the present invention has been described in conjunction with a specific embodiment, it is understood that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, this invention is intended to embrace all such alternatives, modifications and variations which fall within the spirit and scope of the appended claims.