Abstract:
A bolt lock locks a bolt against rotation on an output gear. The bolt lock includes a locking plate having a ring-shaped body encircling the head of the bolt and provided with locking tabs bendable into locking engagement with the flat sides of the bolt head to prevent the bolt from rotating. The plate is secured to the output gear by additional bolts. The ring-shaped body has additional locking tabs bendable into locking engagement with the flat sides of the heads of the additional bolts.

Description:
[0001]     This invention relates to a bolt lock for locking a bolt against rotation.  
       BACKGROUND OF THE INVENTION  
       [0002]     In a typical vehicle transmission, an output gear is splined on a hub. The output gear is clamped in a desired position on the hub by a bolt. However, in time the bolt will loosen if it is not prevented from rotating. When the bolt loosens, the output gear can shift away from its desired position. What is needed is a simple, effective means to prevent the bolt from rotating.  
       SUMMARY OF THE INVENTION  
       [0003]     In accordance with the present invention, a bolt lock is provided for locking a bolt against rotation relative to a base member such, for example, as an output gear in the transmission of an automotive vehicle. The bolt lock comprises a locking plate having at least one flexible, bendable locking tab adjacent to the bolt. The locking tab is bendable into locking engagement with the bolt to prevent the bolt from rotating.  
         [0004]     In a preferred form of the invention, the locking plate has an annular, ring-shaped body adapted to be secured to the output gear in encircling relation to the head of the bolt. The bolt head is polygonal, having flat sides. The ring-shaped body has flexible, bendable locking tabs adjacent to the bolt head which are bendable into locking engagement with the sides of the bolt head.  
         [0005]     Further in accordance with the invention, the ring-shaped body has radially outward extensions provided with one or more additional flexible, bendable locking tabs which engage the heads of additional bolts used to secure the ring-shaped body to the output gear.  
         [0006]     One object of this invention is to provide a bolt lock having the foregoing features and capabilities.  
         [0007]     Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]     The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:  
         [0009]      FIG. 1  is an end elevational view showing an output gear mounted on a hub (not shown in this figure) by a bolt, with a bolt lock comprising a locking plate including a ring-shaped body encircling the head of the bolt. The locking plate has flexible, bendable locking tabs adapted to engage the head of the bolt to prevent the bolt from rotating. The locking plate is secured to the output gear by additional bolts which are also adapted to be prevented from rotating by flexible, bendable locking tabs on extensions of the ring-shaped body;  
         [0010]      FIG. 2  is a sectional view taken on the line  2 - 2  in  FIG. 1  showing the position the flexible locking tabs before any of them are bent into locking engagement with the bolts;  
         [0011]      FIG. 3  is a sectional view similar to  FIG. 2 , but showing selected locking tabs after they have been bent into locking engagement with the bolts;  
         [0012]      FIG. 4  is a sectional view taken on the line  4 -- 4  in  FIG. 1 ;  
         [0013]      FIG. 5  is an elevational view of the locking plate before the locking tabs have been bent into locking positions; and  
         [0014]      FIG. 6  is a sectional view taken on the line  6 -- 6  in  FIG. 5 . 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0015]     The following description of the preferred embodiment is merely exemplary in nature and is in no way intended to limit the invention, its application or uses.  
         [0016]     Referring more particularly to the drawings, there is shown a base member, which is shown in the form of an output gear  10 , splined on a rotary member, which is shown in the form of a tubular hub  12 . The output gear  10  and hub  12  are parts of an automotive vehicle transmission. The hub  12  extends into a center hole  14  in the gear  10 . A bolt  16  is threaded into the hub  12 . The head  18  of the bolt  16  is on the outer side of the output gear  10 , aligned with the hole  14 . The bolt head  18  is polygonal, preferably having six flat sides equally circumferentially spaced 60° apart. A washer  19  surrounds the shank of the bolt  16  and is compressed between the bolt head  18  and the output gear  10  when the bolt  16  is tightened, to clamp the output gear  10  against a locating shoulder  20  on the hub  12  in a desired axial position on the hub  12 .  
         [0017]     A bolt lock  21  is secured to the outer side of the gear  10 . The bolt lock  21  is preferably a metal stamping of integral, one-piece construction and comprises a locking plate  22  having an annular, ring-shaped body  24  which encircles the bolt head  18 .  
         [0018]     The ring-shaped body  24  has a plurality of flexible, bendable locking tabs  26 ,  28 ,  30  and  32  equally circumferentially spaced 90° apart along the radially inner edge of the ring-shaped body  24 .  
         [0019]     The ring-shaped body  24  has a pair of integral, radially outward extensions  34  and  36  spaced 180° apart on opposite sides thereof. The extensions  34  and  36  are in the plane of the body  24  and have center holes  38  and  40 . Flexible, bendable locking tabs  42 ,  44  and  46  project radially outwardly from the extension  34 , spaced 90° apart. Flexible, bendable locking tabs  48 ,  50  and  52  project radially outwardly from the extension  36  spaced 90° apart.  
         [0020]     A bolt  60  extends through the hole  38  in the extension  34  and a bolt  62  extends through the hole  40  in the extension  36 . The bolts  60  and  62  thread into holes  64  and  66  in the output gear  10  and the heads  68  and  70  of the bolts  60  and  62  clamp the locking plate  22  to the output gear  10 . The heads  68  and  70  of the bolts  60  and  62  are polygonal, and, like the bolt  16 , preferably have six flat sides equally circumferentially spaced 60° apart.  
         [0021]      FIGS. 5 and 6  show the locking plate  22  before any of the locking tabs  26 ,  28 ,  30 ,  32 ,  42 ,  44 ,  46 ,  48 ,  50  and  52  have been bent from a retracted position into a locking position. In this condition, the locking tabs  26 ,  28 ,  30  and  32  extend outwardly from the flat plane of the body  24 , and the locking tabs  42 ,  44 ,  46 ,  48 ,  50  and  52  extend at a small angle to the body  24  and the extensions  34  and  36 .  FIG. 2  shows the locking plate  22  secured to the output gear  10  in this same condition, that is, with the locking tabs retracted.  
         [0022]     In use, and with the output gear  10  splined on the hub  12 , the bolt  16  is threaded into the hub  12  and tightened, compressing the washer  19  between the bolt head  18  and the output gear  10  and clamping the output gear  10  against the shoulder  20  of the hub  12  so that the output gear cannot slip axially on the hub. The locking plate  22  is placed flat against the outer side of the output gear  10  as shown in  FIG. 2 . The bolts  60  and  62  are inserted into the holes  38  and  40  of the extensions  34  and  36  and are threaded into the holes  64  and  66  in the output gear  10  and tightened to clamp the locking plate  22  to the output gear  10 , with the body  24  and extensions  34  and  36  flat against the outer surface of the output gear  10 . Then one or more of the tabs  26 ,  28 ,  30  and  32  are bent from the retracted position shown in  FIG. 2  to the locking position of  FIG. 3  against the bolt head  18  so that the bolt  16  cannot rotate. Usually at least two of such tabs are bent to the locking position of  FIG. 3  against the bolt head, and preferably the two selected are on opposite sides of the bolt head  18  and lockingly engage opposite flat sides on the bolt head.  
         [0023]     One or more of the tabs  40 ,  42 , and  46  are bent into engagement with the head  68  of the bolt  60  and one or more of the tabs  48 ,  50  and  52  are bent into engagement with the head  70  of the bolt  62  so that the bolts  60  and  62  cannot rotate.  
         [0024]     While preferably the tabs engage flats on the associated bolt heads, they may also engage the corners between the flats. The tabs when in the locking position prevent the bolts from rotating so that the bolts do not come loose.  
         [0025]     The description of the invention is merely exemplary in nature, and, thus variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.