Patent Publication Number: US-2021190149-A1

Title: Cvt separator tool

Description:
FIELD OF THE INVENTION 
     This application relates to tools for working on continuously-variable transmissions (CVT). 
     BACKGROUND OF THE INVENTION 
     Many types of vehicles, machinery and equipment utilize spring compressed pulley sheaves to disengage and engage an engine or motor and to transmit power to final drive assemblies. The flexible belts or chain links connecting the power source to the transmission or drive unit are subject to failure and wear, requiring frequent repair or replacement. Existing levers and other repair tools for working on these assemblies are difficult to use and expose mechanics to risk of injury or damage to property should the tools become dislodged or lose grip on the spring-compressed pulleys being separated. 
     It would be an advancement in the art to provide improved tools for disassembling spring loaded pulley sheaves. 
     SUMMARY OF THE INVENTION 
     In one aspect of the invention, a method includes providing a clutch including a first sheave mounted to a housing and a second sheave biased into engagement with the first sheave, the housing defining a slot. A bar is inserted into the slot. A bolt is engaged with the bar and is tensioned such that the bolt engages the second sheave and urges the second sheave out of the housing. 
     The bar has a top surface and a bottom surface and inserting the bar includes inserting the bar having the bottom surface facing the second sheave and the top surface facing a top inner surface of the housing, the top surface engaging the top inner surface of the housing upon tensioning of the bolt. 
     The clutch may include a slider engaging the second sheave and positioned within the slot. Inserting the bar into the slot may include inserting the bar across the slider. A bottom surface of the bar may define a recess such that the slider is positioned within the slot when the bar is inserted within the slot. The bottom surface of the bar may define planar portions on either side of the recess. An upper edge of the bar around a top surface of the bar opposite the bottom surface may be rounded. 
     The second sheave may include a portion extending within the housing and secured to the second sheave, the bolt engaging the second sheave by engaging the portion. 
     The bar may define a threaded opening sized to receive the bolt such that engaging the bolt with the bar comprises threading the bolt into the threaded opening. 
     In some embodiments, the bar includes a first end portion and a second end portion opposite the first end portion along a longitudinal direction, the second end portion having a different width than the first portion along a horizontal direction perpendicular to the longitudinal direction. Inserting the bar into the slot includes inserting one of the first end portion and the second end portion into the slot. Each of the first end portion and the second end portion may define a threaded opening extending through the bar in a vertical direction perpendicular to the horizontal direction and the longitudinal direction, the threaded openings of the first end portion and the second end portion being sized to receive the bolt. Engaging the bolt with the bar includes threading the bolt into the threaded opening of one of the first end portion and the second end portion. In some embodiments, the bar further defines a curved transition between the first end portion and the second end portion, the curved transition overlapping the recess along the longitudinal direction. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Preferred and alternative examples of the present invention are described in detail below with reference to the following drawings: 
         FIG. 1  is an isometric view of a separator tool in accordance with an embodiment of the present invention; 
         FIG. 2  is an isometric view of the separator tool with a separator bolt in accordance with an embodiment of the present invention; 
         FIGS. 3A to 3C  are orthogonal views of the separator tool in accordance with an embodiment of the present invention; 
         FIG. 4  is a side view of the separator tool and bolt in accordance with an embodiment of the present invention; 
         FIG. 5  is a perspective view of the separator tool in use on a clutch of a CVT in accordance with an embodiment of the present invention; and 
         FIGS. 6A and 6B  are side cross-sectional views of a clutch of a CVT in combination with the separator tool illustrating its method of use in accordance with an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to  FIGS. 1 and 2 , a clutch removal tool  10  may be understood with respect to a vertical direction  12   a , a longitudinal direction  12   b , and a horizontal direction  12   c , that are all mutually perpendicular. The tool  10  may include a bar  14  having two end portions  16   a ,  16   b  that have different widths in the horizontal direction  12   c  and are on opposite ends of the bar  14  along the longitudinal direction  12   a . As discussed below, the end portions  16   a ,  16   b  insert within a clutch during disassembly. The different sizes of the end portions  16   a ,  16   b  enable the bar  14  to be used with two different types of clutches. The bar  14  may be made of aluminum, steel, composite (carbon fiber, fiberglass, etc.), rigid polymer, or other material having sufficient strength to resist the forces developed during use as described herein. 
     Each end portion  16   a ,  16   b  defines a threaded aperture  18   a ,  18   b  having central axes extending through the bar  14  substantially (within 2 degrees of) parallel to the vertical direction  12   b . A bottom side of the bar  14  may define a notch  20  or recess  20  that facilitates clearance of components of a clutch during insertion as described below. A top side of the bar  14  may define a chamfered edge  22  that is rounded to provide clearance and to facilitate insertion. The bottom side of the bar  14  further includes portions  24   a ,  24   b  on either side of the recess  20 . The portions  24   a ,  24   b  may be planar and substantially parallel to the longitudinal and horizontal directions  12   b ,  12   c . As shown in  FIG. 2 , a bolt  26  may be threaded into either of the threaded apertures  18   a ,  18   b  and may be threaded through to the extent that the bolt  26  protrudes out of the bottom side of the bar  14 . 
       FIGS. 3A, 3B, and 3C  illustrate example dimensions of the various features of the bar  14  and  FIG. 4  illustrates dimensions of the bolt  26 . In  FIGS. 3A, 3B, 3C , and  FIG. 4 , units are in inches. The illustrated dimensions are exemplary only. As is apparent from the dimensions, the bar  14  is longer in the longitudinal direction  12   b  than in the vertical and horizontal directions  12   a ,  12   c . Both end portions  16   a ,  16   b  may be wider in the horizontal direction  12   c  than they are thick in the vertical direction  12   a . As is also apparent, the corners of the bar are rounded in a plane parallel to the longitudinal and horizontal directions  12   b ,  12   c . Likewise, the top edge is rounded around the top surface of the bar  14 . The rounding of the top edge may facilitate insertion of the bar during use as discussed below. 
       FIG. 5  illustrates a method of use of the tool  10 . A housing  30  of a clutch includes a slot  32  through which the end portion  16   a  is inserted in the illustrated example. For a different design of clutch, the larger end  16   b  may be used. As is apparent, there is a slider block  34 , which may also be a roller in some embodiments, that slides within the slot  32 . The recess  20  may be sized such that the end  16   a  or  16   b  may be inserted around the slider block  34 . Accordingly, the length of the recess  20  along the longitudinal dimension  12   b  may be selected to be larger than a width of the slider block  34 . 
       FIG. 5  further illustrates operation of the bolt  26 . The bolt may be either (a) completely removed during insertion into the slot  32  or (b) inserted into the opening  18   a ,  18   b  such that it does not protrude out of the corresponding surface  24   a ,  24   b  during insertion. In either case, following insertion, the bolt  26  may be tensioned such that it protrudes out of the surface  24   a ,  24   b  and presses against a component of the clutch in order to separate sheaves of a pulley of the clutch. 
     For example, referring to  FIG. 6A , the housing  30  has a sheave  36   a  mounted thereto or formed monolithically therewith. Another sheave  36   b  is positioned opposite  36   b  and includes a portion  38  extending into the housing and having the slider  34  mounted thereto. The sheave  36   b  is subject to a biasing force  40  urging the sheave  36   b  against the sheave  36   a . For example, a spring (not shown) may urge the shave  36   b  against the sheave  36   a . The configuration of the clutch, including parts  36   a ,  36   b ,  38 , and  40  may be according to any CVT known in the art, particularly those used in snowmobiles, off road utility vehicles, all-terrain vehicles, or other light off-road vehicles. 
     Following insertion, the bolt  26  is tensioned such that it protrudes out of the bottom of the bar  14 . As shown in  FIG. 6B , as the bolt  26  is further tensioned, the bolt  26  engages the portion  38  and urges it outwardly from the housing  30 . As is apparent in  FIGS. 6A and 6B , a portion of the bar  14  (e.g., end portion  16   a  as shown in  FIG. 5 ) pushes against an upper inner surface  42  of the housing  30  to counter the force exerted by the bolt  26 . Removal is the opposite of installation. The bolt  26  is loosened until it no longer engages the portion  38 , does not protrude from the bottom of the tool  14 , or is completely removed. The bar  14  is then removed from the slot  32 . 
     While the preferred embodiment of the invention has been illustrated and described, as noted above, many changes can be made without departing from the spirit and scope of the invention. Accordingly, the scope of the invention is not limited by the disclosure of the preferred embodiment. Instead, the invention should be determined entirely by reference to the claims that follow.