Abstract:
A block including first and second generally identical side plates that engage one another and rotatably capture a sheave between them. The side plates may includes interlocking tabs to secure the engagement between the side plates or a separate clip may be used to engage elements of the side plates to secure the plates to each other.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    The present application claims priority to earlier filed U.S. Provisional Application Ser. No. 61/413,370, filed on Nov. 12, 2010, the disclosure of which is incorporated herein by reference in its entirety. 
     
    
     BACKGROUND 
       [0002]    Improvements to existing blocks for use in sailing or other applications are desirable to achieve some or all of the following: reduce the cost of construction, reduce the part count; eliminate or reduce separate fasteners needed to assemble a block, and improve overall strength of the block. These do not represent the entire list advantages that may be achieved or which may be desirable to be achieved by an improved block. 
         [0003]    The present disclosure relates to an approach to the design, construction and assembly of blocks that may address some or all of the above goals, in addition to achieving other improvements that may be apparent to those having skill in the related art. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0004]    The accompanying drawing figures, which are incorporated in and constitute a part of the description, illustrate several aspects of the invention and together with the description, serve to explain the principles of the invention. A brief description of the figures is as follows: 
           [0005]      FIG. 1  is a first side view of a block according to the present disclosure, with a portion of the block removed to illustrate the positioning of a clip to secure the side plates to the block. 
           [0006]      FIG. 2  is an edge view of the block of  FIG. 1 . 
           [0007]      FIG. 3  is a top view of the block of  FIG. 1 . 
           [0008]      FIG. 4  is a second side view of the block of  FIG. 2 . 
           [0009]      FIG. 5  is a cross-sectional view of the block of  FIG. 1  taken along line A-A of  FIG. 4 . 
           [0010]      FIG. 6  is a bottom view of the block of  FIG. 1  with the sheave removed for clarity. 
           [0011]      FIG. 7  is an exploded perspective view of the block of  FIG. 1 . 
           [0012]      FIG. 8  is a perspective view of a second embodiment of a block according to the present disclosure. 
           [0013]      FIG. 9  is an edge view of the block of  FIG. 8 . 
           [0014]      FIG. 10  is a top view of the block of  FIG. 8 . 
           [0015]      FIG. 11  is a side view of the block of  FIG. 8 . 
           [0016]      FIG. 12  is a bottom view of the block of  FIG. 8  with the sheave removed for clarity. 
           [0017]      FIG. 13  is an exploded perspective view of the block of  FIG. 8 . 
       
    
    
     DESCRIPTION 
       [0018]    Reference will now be made in detail to exemplary aspects of the present invention which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. 
         [0019]      FIGS. 1 to 7  illustrate an improved block  100 , preferably for use on sailboats but adaptable for use in other applications and settings. Block  100  may include a pair of generally identical side plates  102  with a sheave  104  rotatably mounted between the side plates. At a top  106  of the side plates  102  are a pair of interlocking tabs  108  that are configured to releasably secure the side plates  102  to each other. Within an opening  112  of side plates  102  about which sheave  104  rotates is positioned a clip indicated by number  4  within a circle. Clip  4  is configured to interact with and cooperate with an element  130  of the side plates  102  to secure the bottom of the side plates to each other. Clip  104  may preferably be inserted within grooves or recesses  132  on either side of element  130 . Clip  104  is preferably inserted into engagement with elements  130  from within opening  112  and pressed downward into grooves  132 . 
         [0020]    Opening  112  is preferably configured to receive a line or other flexible securing member to secure block  100  to a sailboat or some other surface or device. A post  140  may be positioned within opening  112  to permit a bight or loop of line passing through an opening  142  adjacent top  106  and into opening  112 . A second bight or loop of line may be passed through opening  142  and into opening  112  from an opposite side and secured about post  140 . 
         [0021]    Sheave  104  may be preferably mounted to the side plates on top of ball bearing  110  to permit smooth rotation. Other types of bearings may be used within the scope of the present disclosure, such as but not limited to roller, needle, bushing, hybrid, etc. 
         [0022]    As shown in  FIG. 7 , the interior surfaces of side plates  102  may include additional engaging features such as but not limited to pins  114  that may be configured and positioned to engage openings  122  to ensure proper relative orientation and positioning of the side plates. These engaging features may also provide added structural integrity to the assembly block  100 . It is anticipated that no additional engaging features may be needed for some configurations or embodiments of blocks according to the present disclosure. It is further anticipated that the pins and openings may have integral interlocking elements to further secure the side plates to each other. It is also anticipated that the interlocking features may be combined with the engaging features. 
         [0023]    Side plate  102  may include a bearing track  134  within a portion of sheave receiving space  136 , with the bearing track  134  positioned toward top  106  along an inner wall  138 . Since the primary loads placed on a rope or line running through sheave  104  will come from opposite top  106 , the highest loading about the circumference of the sheave will be adjacent bearing track  134 . Bearing track  134  will ensure that bearings  110  remain in a preferred alignment between sheave  104  and side plate  102 . Bearing tracks  134  may also include some reinforcement or strengthening materials to aid in the resisting of these loads placed on the sheave and improve wear resistance. 
         [0024]      FIGS. 8 to 13  illustrate a block  200  according to the present disclosure which does not require any additional elements (such as clip  4 , described above with regard to block  100 ) beyond a pair of preferably identical side plates  202  to secure the block assembly. A sheave  104  may be mounted between the side plates  202  with an opening  212  in the side plates extending through a center of the sheave. Adjacent a top  206  of each side plate  202  of block  200  is a first interlocking tab  208 . Tabs  208  from the pair of side plates  202  of block  200  engage each other and cooperate to releasably secure the assembly of the side plates about the sheave. At a bottom of each side plate  202  opposite top  206  is a second interlocking tab  220 . Tabs  220  from the pair of side plates  202  of block  200  enage each other and cooperate to releasably secure the assembly of the side plates about the sheave. 
         [0025]    As shown in  FIG. 12 , the interior surfaces of side plates  202  may include additional engaging features such as but not limited to pins  214  that may be configured and positioned to engage openings  222  to ensure proper relative orientation and positioning of the side plates. These engaging features may also provide added structural integrity to the assembly block  200 . It is anticipated that no additional engaging features may be needed for some configurations or embodiments of blocks according to the present disclosure. It is further anticipated that the pins and openings may have integral interlocking elements to further secure the side plates to each other. It is also anticipated that the interlocking features may be combined with the engaging features. 
         [0026]    Side plate  202  may include a bearing track  234  within a portion of sheave receiving space  236 , with the bearing track  234  positioned toward top  206  along an inner wall  238 . Since the primary loads placed on a rope or line running through sheave  204  will come from opposite top  206 , the highest loading about the circumference of the sheave will be adjacent bearing track  234 . Bearing track  234  will ensure that bearings  110  remain in a preferred alignment between sheave  204  and side plate  202 . Bearing tracks  234  may also include some reinforcement or strengthening materials to aid in the resisting of these loads placed on the sheave and improve wear resistance. 
         [0027]    When assembled as shown herein, both block  100  and  200  are configured so that the engagement or interlocking of the tabs or the pins and corresponding openings will prevent the side plates from rotating with respect to each other and retain the sheave and any supporting bearings between the side plates. 
         [0028]    While the invention has been described with reference to preferred embodiments, it is to be understood that the invention is not intended to be limited to the specific embodiments set forth above. Thus, it is recognized that those skilled in the art will appreciate that certain substitutions, alterations, modifications, and omissions may be made without departing from the spirit or intent of the invention. Accordingly, the foregoing description is meant to be exemplary only, the invention is to be taken as including all reasonable equivalents to the subject matter of the invention, and should not limit the scope of the invention set forth in the following claims.