Abstract:
A coupler comprising a shaft, an enlarged head, a proximal end of the shaft, and a journal for contacting and rotating in an annular bearing surface of a component for forming a pin connection with the component. In addition, the coupler includes a plurality of projecting fins projecting from the journal along axes generally parallel to the longitudinal axis of the shaft and are radially spaced around the journal.

Description:
TECHNICAL FIELD AND BACKGROUND OF THE INVENTION 
     The present invention relates to a coupler and, more particularly, to a coupler that provides a pin connection and which can be used to mount a blade to grass mowing equipment, for example. 
     In grass mowing equipment, and especially large grass mowing equipment, for example the mowing equipment often used along highways, the loss of a mower blade while the equipment is being operated is dangerous. Therefore, it is important for the blade to be mounted to the rotating hub of the mower by a bolt that has the proper capacity. 
     Accordingly, there is a need to assure that the proper bolt or coupler is being used, especially in situations when failure of the connection using the bolt or coupler could expose someone to risk of injury. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention provides an improved coupler that reduces the risk of the wrong coupler being used in a connection that can be subject to large loads and hence high stresses. 
     In one form of the invention, a coupler includes a shaft and an enlarged head formed on the end of the shaft. The head includes a journal for contacting and rotating in an annular bearing surface of a component to thereby form a pin connection with the component and further a plurality of projecting fins that project from the journal along axes generally parallel to the longitudinal axis of the shaft and which are radially spaced around the journal. 
     In one aspect, the shaft comprises a round cylindrical shaft. In other aspects, the shaft may have a multi-sided cylindrical shaft, such as a square, hexagonal or pentagonal sided cylindrical shaft. 
     In other aspects, the coupler includes two, three, four, five or six fins. In a further aspect, the shaft includes a key for cooperating with a keyway in the component. 
     According to yet other aspects, the journal has an annular outer surface, with each of the fins having an outer surface that is contiguous with the annular outer surface of the journal and lies in the same curved space as the curved surface of the annular outer surface of the journal. 
     According to a further aspect, when the coupler is mounted to the component, the fins are folded to thereby form outwardly projecting shoulders, which project outwardly from the curved surface of the annular outer surface of the journal. 
     In another form of the invention, a blade assembly includes a blade with a mounting opening and a coupler mounted in the opening. The coupler includes a shaft and an enlarged head formed on the end of the shaft. The head includes a journal, which has a greater transverse dimension than the shaft. The shaft is extended through the mounting opening with the journal located in the mounting opening and bearing on the annular bearing surface of the blade provided by the mounting opening. The journal is capture in the mounting opening by the enlarged head, which is positioned on one side of the blade, and by a plurality of outwardly extending shoulders formed at the terminal end of the journal which project radially outward from the annular surface of the journal and which are located on the other side of the blade. 
     In one aspect, the shoulders comprise folded members projecting from the journal. 
     In other aspects, the journal may include two, three, four, five or six shoulders. 
     In other aspects, the shaft includes a threaded portion for receiving a nut and for connecting the blade to mower equipment. 
     In another form of the invention, a method of mounting a coupler, which has a shaft and an enlarged head and a plurality of longitudinally extending fins that extend from the head along axes generally parallel to the longitudinal axis of the shaft, to a component, which has a mounting opening with a bearing surface, includes extending the shaft through the mounting opening wherein the fins project through the mounting opening. The fins are then folded to form a plurality of shoulders wherein the head is positioned on one side of the component and the shoulders are positioned on the other side of the component to thereby mount the coupler to the component. 
     A method of forming a coupler includes a forming a shaft, forming an enlarged head one end of the shaft, and forming a plurality of fins on the head that extend along axes generally parallel to the longitudinal axis of the shaft, wherein the fins are formed by cold forming a portion of the head. 
     These and other objects, advantages, purposes, and features of the invention will become more apparent from the study of the following description taken in conjunction with the drawings. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side elevation view of a coupler design of the present invention; 
         FIG. 2  is a top plan view of the coupler of  FIG. 1 ; 
         FIG. 3  is a bottom plan view of the coupler of  FIG. 1 ; 
         FIG. 4  is another side elevation view of the coupler of  FIG. 1 ; 
         FIG. 5  is a front elevation view of the coupler of  FIG. 1 ; 
         FIG. 5A  is a side partial fragmentary view of the coupler of the present invention mounted in a blade; 
         FIG. 5B  is a top plan view of the blade and coupler of  FIG. 5A  shown mounted to a piece of equipment; 
         FIG. 5C  is an enlarged detail view of area VC of  FIG. 5A ; 
         FIG. 6  is a front elevation view of another embodiment of the coupler design of the present invention; 
         FIG. 7  is a top plan view of  FIG. 6 ; 
         FIG. 8  is a bottom plan view of the coupler of  FIG. 6 ; 
         FIG. 9  is a front elevation view of another design of the coupler of the present invention, which is substantially identical to the rear elevation view of the coupler; 
         FIG. 10  is a top plan view of the coupler of  FIG. 9 ; 
         FIG. 11  is a bottom plan view of the coupler of  FIG. 9 ; 
         FIG. 12  is a front elevation view of another embodiment of a coupler design of the present invention; 
         FIG. 13  is a bottom plan view of the coupler of  FIG. 12 ; 
         FIG. 14  is a left side elevation view of the coupler of  FIG. 13 ; 
         FIG. 15  is a front elevation view of another embodiment of a coupler of the present invention; 
         FIG. 16  is a bottom plan view of the coupler of  FIG. 15 ; 
         FIGS. 17-21  illustrate the steps of forming the coupler of the present invention; and 
         FIG. 22  is a partial fragmentary bottom plan view of the coupler of  FIG. 21  in its final form. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to  FIG. 1 , the numeral  10  generally designates a coupler of the present invention. As will be more fully described below, coupler  10  is adapted to be mounted to a component, such as a blade of a mower, for mounting the component to, for example, a piece of equipment E ( FIG. 5B ) in a manner to limit the removal of the coupler. Suitable mowing equipment includes residential mowing equipment or commercial mowing equipment, including for example, any of the Toro or John Deere mowing equipment. Coupler  10  has particular application high load applications where it is important to assure that the correct coupler has been used to mount the component to the equipment. 
     Referring to  FIGS. 1-5 , coupler  10  comprises a bolt and includes a shaft  12  and an enlarged head  14 . Head  14  is formed on one end of the shaft and includes a downwardly extending annular collar  16 , which forms a shoulder. As will be more fully described below in reference to  FIGS. 5A-5C , shoulder  16  provides a journal for coupler  10  when mounted to a component. 
     As best seen in  FIGS. 1 ,  4 , and  5 , projecting downwardly from shoulder  16  (as viewed in  FIGS. 1 ,  4 , and  5 ) are a plurality of fins  18 . As will be more fully described in reference to the method of making coupler  10 , fins  18  may be formed from a portion of the material that forms shoulder  16 . In the illustrated embodiment, coupler  10  includes three fins, which are generally equally, spaced around the shaft. Each fin has tapered sides starting at the juncture with the shoulder  16  and which terminate at a distal end  18   a . In the illustrated embodiment, distal ends  18   a  are generally flat and form edges between the respective angled sides  18   b  and  18   c ; however, it should be appreciated that the shape and number of the fins may be varied. 
     Further, in the illustrated embodiment, shaft  12  comprises a round cylindrical shaft, but it should be understood from the alternate embodiments described below, the shaft&#39;s shape may be varied. 
     Referring to FIGS.  1  and  3 - 5 , shaft  12  may include a key  20 , which may be formed form the material forming shaft  12 . When forming key  20 , a localized planar surface  22  is created on shaft  20  on either side of the key. Key  20  may comprise a number of different shapes, but in the illustrated embodiment comprises an elongate body  24  ( FIG. 5 ) with a generally central recess  26  that extends longitudinally along the longitudinal axis of elongate body  24 . As best seen from  FIG. 3 , recess  26  is generally centrally located in body  24  and, further, is formed between arcuate surfaces  26   a  and  26   b , which are formed when the material from shaft  12  is removed and compressed to thereby form the key. 
     Referring to  FIGS. 5A-5C , coupler  10  is particularly suitable for use in mounting a blade  30  to a grass mower, for example. As best seen in  FIG. 5A , blade  30  includes a mounting opening  32  in which coupler  10  is inserted and, further, placed such that annular member  16  is located in opening  32  to provide a journal or bearing contact with the blade. Once shaft  12  is inserted through the mounting opening, and shoulder  16  is positioned in mounting opening  32 , fins  18  project outwardly from the blade on the other side of the mounting opening from enlarged head  14 . The fins are then folded to form a shoulder  34  as best seen in  FIG. 5C . Referring to  FIG. 5B , when fins  18  are folded, shoulders  34  are arranged radially around the longitudinal axis of bolt  10  and provide a three point contact between the coupler and blade  30  in the direction of the longitudinal axis of coupler  10 . 
     In this manner, when coupler  10  is mounted to blade  30 , coupler  10  cannot be removed without removal of the shoulders. 
     For example, for a coupler with nominal diameter of 1 inch, shoulders  34  may be configured to have a minimum lateral dimension as measured along lateral axes  10   a  of coupler  10  of about 0.06 inches and may fall in the range of about 0.06 to 2.0 inches, depending on the size of the coupler. It should be understood that these dimensions are given as examples only and the dimensions may vary depending application and material used. 
     Referring to  FIG. 6 , the numeral  110  generally designates another embodiment of the coupler of the present invention. Coupler  110  is similar to coupler  10  and includes a shaft  112  and an enlarged head  114 . In the illustrated embodiment and as best seen in  FIG. 8 , shaft  112  comprises a square shaft with each of the respective fins  118  generally aligned with a respective side  112   a  of the shaft. In the illustrated embodiment, therefore, coupler  10  includes four fins, one associated with each side of the shaft. The remaining details of coupler  110  are similar to the details of coupler  10 . Therefore, for further details of coupler  110 , reference is made to coupler  10 . 
     It should be understood that the number of fins may be varied. For example, referring to  FIGS. 9-11 , coupler  210 , which is similar to coupler  110 , includes a pair of fins  218 , which are generally aligned with opposed sides  212   a  of shaft  212 , which is a square shaft similar to shaft  112 . As noted above, the shape of the shaft may be varied. 
     Referring to coupler  310 ,  FIGS. 12 and 13  includes a hexagonal-sided shaft  312 , with a fin  318  associated with each side  312   a  of shaft  312 . As noted above, the number of fins may be modified though it is preferred to have a balanced arrangement. For example, two or three fins may be used provided they are spaced generally evenly around the center axis of the coupler. 
     Referring to  FIG. 15 , coupler  410  includes a shaft  412  with a pentagon-shaped shaft  412 . As best seen in  FIG. 16 , in order to provide a balanced support system, coupler  410  includes five fins  418 , with each fin associated with a side  412   a  of coupler  412  in a similar manner described in reference to the previous embodiments. 
     Referring to  FIGS. 17-22 , coupler  10  is formed from bar stock, for example of carbon steel. The shaft portion of coupler  10  is formed by extrusion of the bar stock into the desired cross-section. For example, in the illustrated steps, the lower portion is extruded into a circular shaft. The upper portion of the bar stock is then formed, such as by cold forging (upsetted), into the enlarged head  14  and shoulder  16 . A portion of the shoulder is then cold forged into fins  18 , which provides a uniform grain flow and which does not significantly, if at all, impact the structural strength of the shoulder region. Similarly, key  20  is cold forged from a portion of the shaft mass. Again, the mass that is removed from the shaft to form the key does not significantly, if at all, impact the structural strength of the shaft. 
     The lower end of the lower portion of the shaft is then threaded for receiving a nut for securing the coupler to the desired surface. 
     For example, for a 1 inch nominal diameter coupler, the height of enlarged head  14  may be approximately ½ inch with an outer diameter of approximately 2.47 inches to 2.530 inches. The height of the shoulder  16  may fall in the range of 0.53 to 0.545 inches with an outer diameter (OD) of 1.488 to 1.498. The overall length of the shoulder at the center of each fin may fall in a range of 0.1 inch to 0.085 inches. The key, for example, may have a height in a range of 0.72 inches to 0.82 inches with its center located below the terminal edge of the collar in a range of about 0.38 inches to 0.5 inches. 
     As described above, when coupler  10  is mounted to the component, for example blade  30 , fins  18  are compressed and folded to form shoulders  34  with a minimum width as measured from the outer circumference of shoulder  16  of about 0.06 inches. For example, the height of the shoulder may be approximately 0.03 inches. It should be understood that the foregoing dimensions are provided merely as exemplary dimensions only and are not intended to limit the scope of the invention. 
     Accordingly, the present invention provides a coupler that may be mounted and secured to a component, which may be particularly useful when used in high load applications when the coupler specifications must be controlled to assure the safe operation of the component. 
     While several forms of the invention have been shown and described, other forms will now be apparent to those skilled in the art. Therefore, it will be understood that the embodiments shown in the drawings and described above are merely for illustrative purposes, and are not intended to limit the scope of the invention which is defined by the claims which follow as interpreted under the principles of patent law including the doctrine of equivalents.