Patent Publication Number: US-7721627-B2

Title: Attachments for power tools

Description:
TECHNICAL FIELD 
   The present invention relates to tool attachments and, more specifically, to off-set drive bolting attachments for power tools. 
   BACKGROUND 
   The position and placement of a fastener, such as a bolt, screw, or nut, does not always permit the use of conventional tools to facilitate the installation and removal of the fastener. This is particularly true when there is only minimal clearance in the area surrounding the fastener such that it is impossible to engage the fastener with a conventional tool (e.g., as in the attachment of vehicle doors to the vehicle body during assembly). Particularly, the relative position and proximity of a vehicle body to a vehicle door (e.g., the hinge portion of the door) does not permit the use of a conventional impact gun where the drive mechanism is located directly behind the socket that engages the fastener. 
   To overcome this problem, tool attachments have been produced that facilitate the use of conventional power tools to engage a fastener located in an otherwise inaccessible position. These attachments, also known as crow&#39;s foot attachments, can be affixed to the power tool and engaged with the drive mechanism of the power tool.  FIG. 1  shows an example of a prior art crow&#39;s foot tool attachment. The attachment  2  comprises a shaft  4  having a socket  6  fixed thereon. The socket  6  is connected to the shaft  4  with a swivel joint (not shown), such as a ball and socket joint, that permits the socket  6  to be adjustably positioned on the end of the shaft  4 . The opposite end  10  of the shaft is configured to attach to the drive mechanism  12  of a power tool  14  having an axis of rotation  18  and a plane of rotation  20 . When engaged with a fastener  16 , the socket rotates about a second, different axis of rotation  38  and in a second, different rotation plane  30 . 
   While generally suitable for the purpose of engaging otherwise inaccessible fasteners, the existing tool attachments have several drawbacks including tool slippage and stripping of the fastener  16 . This is because the force F applied to the power tool  14  to keep the socket  6  engaged with the fastener  16  has both a perpendicular component  44  and a parallel component  45  relative to the socket  6 . The perpendicular component  44  of the force F causes the operator to have poor control over both the fastener  16  and the power tool  14  at the interface of the fastener  16  with the socket  6  resulting in slippage of the socket  6  on the fastener  16 . Slippage of the socket  6  on the fastener  16  may cause the fastener  16  to become stripped necessitating removal and replacement of the fastener  16 . If the socket  6  becomes fully disengaged from the head of the fastener  16  during installation or removal of the fastener  16 , damage may occur to the workpiece  50  as the rotating attachment  2  comes in contact with portions of the workpiece  50 . 
   Other embodiments of prior tool attachments include those that are configured to be affixed to specialized power tools and engaged with the drive mechanism of the power tool such that the rotational motion of the drive mechanism is translated to a different rotational axis and plane. Such attachments use gears, shafts, and spline gears to translate the rotational motion of the power tool. However, these tools suffer from the same slippage problems as the apparatus shown in  FIG. 1 . Further, such attachments are expensive (as are the specialized power tools required for operation), the translation mechanism is often intricate, heavy, and susceptible to breakage, and repair of the mechanism can be difficult and time consuming. 
   Accordingly, a need exists for an inexpensive, ergonomically correct, versatile, and easily operated tool attachment for facilitating the insertion and removal of fasteners in otherwise inaccessible locations. 
   SUMMARY 
   The present invention may include an attachment for a power tool to facilitate the insertion of fasteners in otherwise inaccessible locations. The attachment may have an adapter with a first end and a second end. The second end of the adapter may be operable for fastening the attachment to a power tool. The first end of the adapter may have a bolting insert secured thereto. The bolting insert may comprise a drive gear configured to engage the drive mechanism of the power tool and a bolting gear. The drive gear and the bolting gear may be arranged such that rotation of the driving gear causes the rotation of the bolting gear. 
   In another embodiment, the present invention may include an attachment for a power tool. The attachment may have an adapter with a first end and a second end. The second end of the adapter may be operable for fastening the attachment to the power tool. The first end of the adapter may have a bolting insert secured thereto. The bolting insert may contain a drive gear configured to engage the rotating drive mechanism of the power tool. The bolting insert may also contain a bolting gear and a center gear disposed between the bolting gear and the drive gear. The drive gear, bolting gear and center gear may be arranged such that rotation of the drive gear causes the rotation of the center gear and the bolting gear. 
   In another embodiment, the present invention may include an attachment for translating the rotation of a power tool from a first axis of rotation to a second, parallel axis of rotation in the same or a parallel plane. The attachment may comprise an adapter for affixing the attachment to the power tool. The attachment may also comprise a bolting insert associated with the adapter. The bolting insert may include a drive gear for interfacing with a power tool and a bolting gear for interfacing with a fastener. The drive gear may comprise a first axis of rotation and the bolting gear may comprise a second axis of rotation parallel to the first axis of rotation. The drive gear and bolting gear may be operatively engaged with one another in a common rotational plane such that rotation of the drive gear causes the rotation of the bolting gear. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The following detailed description of specific illustrative embodiments of the present invention can be best understood when read in conjunction with the following drawings in which: 
       FIG. 1  is a schematic diagram of a prior art tool attachment attached to a power tool and shown in use; 
       FIG. 2  is a schematic diagram showing an attachment in accordance with one exemplary embodiment of the present invention affixed to a power tool; 
       FIG. 3A  is a top perspective view of the adapter portion of an attachment in accordance with one exemplary embodiment of the present invention; 
       FIG. 3B  is a bottom perspective view of the adapter portion of  FIG. 3A  in accordance with one exemplary embodiment of the present invention; 
       FIG. 4A  is an exploded view of a bolting insert portion of an attachment in accordance with one exemplary embodiment of the present invention; 
       FIG. 4B  is a perspective view showing the position and orientation of gears of the bolting insert portion of  FIG. 4A  in accordance with one exemplary embodiment of the present invention; and 
       FIG. 5  shows an attachment in accordance with one exemplary embodiment of the present invention as applied to install a fastener. 
   

   DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS 
     FIG. 2  shows an attachment  100  in accordance with one exemplary embodiment of the present invention. The attachment  100 , illustrated as being affixed to a power tool  152  having a drive mechanism  154 , may generally comprise an adapter portion  102  with a bolting insert portion  120 . Each of these portions will be described more fully herein. As discussed herein, tool attachments of the present invention facilitate the insertion and removal of fasteners in difficult or generally inaccessible positions, such as those used to secure a vehicle door to a vehicle body. 
   Referring now to FIGS.  2  and  3 A- 3 B, the adapter portion  102  of the attachment  100  in accordance with one exemplary embodiment of the present invention is shown. The adapter portion  102  may be configured with a receptacle  104  for receiving a bolting insert portion  120  (shown in  FIGS. 2 ,  4 , and  5 ) and a base  107  for securing the adapter to a power tool with a column  109  therebetween. As shown in  FIG. 3B , the adapter portion  102  may contain an opening  108  within the base  107  for receiving a power tool  152 . A hollow channel  110  may extend along the length of the adapter portion  102  (e.g., through base  107  and column  109 ) connecting the opening  108  with the receptacle  104 . Set screws  106  may be located within the base  107  and adjacent the opening  108  to set the adapter portion  102  in place on the power tool  152 . In another embodiment the base  107  may comprise threads on the inner diameter of the base  107  to secure the adapter  102  to a power tool (e.g., through corresponding threads on the power tool). The adapter portion  102  may also be configured with threaded holes  112  located in the receptacle  104  and configured to attach the bolting insert portion  120  to the adapter portion  102 . The adapter portion  102  may be constructed from a lightweight material such as aluminum or titanium alloys. 
   It should be understood that adapters  102  illustrated in  FIGS. 3A and 3B  and described herein are exemplary in nature and that any arrangement of an adapter so configured to secure a bolting insert thereto, and/or to provide attachment between a bolting insert and a power tool can be utilized. 
   Referring to FIGS.  2  and  4 A- 4 B, the bolting insert portion  120  of the attachment  100  in accordance with one exemplary embodiment of the present invention is shown. The bolting insert portion  120  may comprise a base  122  made of materials such as steel or titanium alloys. The base  122  may have at least two gears disposed therein, for example, a drive gear  126  and a bolting gear  128 , operatively engaged with one another (e.g. through teeth  129 ) such that rotation of the drive gear  126  causes rotation of the adjacent bolting gear  128 . As illustrated in  FIG. 4B , the drive gear  126  and bolting gear  128  may be oriented in the same rotational plane. In one embodiment, as shown in  FIGS. 4A and 4B , the drive gear  126  and the bolting gear  128  may be 12 mm hexagonal insert gears having a hexagonal mating surface  148  for receiving a hexagonal attachment extending through the center portion of the gear. Of course, any arrangement having any number of teeth or mating surfaces can be utilized. The drive gear  126  and bolting gear  128  may be positioned in the bolting insert portion  120  such that a portion of each gear  126 , 128  extends through openings  170   a ,  170   b  in the base  122  and through openings  172   a ,  172   b  in the cover  124  thereby securing each gear  126 , 128  between the base  122  and the cover  124  and providing an axis of rotation for each gear  126 , 128 . 
   As illustrated in  FIGS. 4A and 4B , the bolting insert portion  120  may further comprise at least one center gear  130  disposed between the drive gear  126  and the bolting gear  128  and operatively engaged with both the drive gear  126  and the bolting gear  128  such that rotation of the drive gear  126  may cause the rotation of the center gear  130  and the bolting gear  128 . The center gear  130  may be fixed in position by a shaft  132  which may serve as the rotational axis of the center gear  130 . The shaft  132  is secured in a recessed portion  176  in the base  122  and a corresponding recessed portion (not shown) in the cover  124  of the bolting insert portion  120 . The center gear  130  may rotate about the shaft  132  on a bearing  144  removably inserted in the center gear  30 . 
   In the 3-gear configuration of the bolting insert  120  shown in  FIGS. 4A and 4B , the center gear  130  may serve several purposes. The bearing  144  on which the center gear  130  rotates also reduces friction in the bolting insert  120 . As shown in  FIGS. 4A and 4B , the center gear  130  may also increase the offset distance between the drive gear  126  and the bolting gear  128 . As shown in  FIG. 4B , the center gear  130 , as an intermediary between the drive gear  126  and the bolting gear  128 , may reverse the direction of rotation of the driving gear  126  thereby allowing the driving gear  126  and bolting gear  128  to rotate in the same direction. Finally, the center gear  130  being rotatably fixed to the shaft  132  which is, in turn, fixed to the based  122  and cover  124 , may provide stability to the mechanism of the bolting insert portion  120 . 
   Referring to  FIGS. 4A , a socket insert  134  may be provided and removably inserted through the opening  172   a  in the cover  124 , the bolting gear  128 , and the opening  170  in the base  122 . The socket insert  134  may have a hexagonal shaft  135  that engages with the hexagonal mating surface  148  of the bolting gear  128  as shown in  FIG. 4A . The socket insert  134  may also comprise a magnet  138  for retaining fasteners. The socket insert  134  may be slidably secured by a retaining ring  136  placed around the hexagonal shaft  135 . The socket insert  134  may also be interchangeable with other socket inserts configured to engage different types of fasteners. The cover  124  of the bolting insert portion  120  may be secured to the base  122  by screws  142  (one of which is shown) or any other securing arrangement. 
   Referring now to  FIG. 4B , and as described more fully below, rotational motion of the drive gear  126  is imparted to the center gear  130  causing the center gear  130  to rotate in the opposite direction as the drive gear  126 . The rotational motion of the center gear  130  is, in turn, imparted to the bolting gear  128  which rotates in the opposite direction of the center gear  130  (but in the same direction as the drive gear  126 ). As shown in  FIG. 4A , when the hexagonal shaft  135  of the socket insert  134  is engaged with the hexagonal mating surface  148  of the bolting gear  128  the rotation of the bolting gear  128  also rotates the socket insert  134 . 
   It should be understood that the bolting inserts described herein can have any number of gears in any number of sizes and arrangements configured to manipulate the distance between a drive gear (e.g., the gear that engages the power tool) and the bolting gear (e.g., the gear that engages the fastener or socket insert) so as to effectively transfer the drive from a power tool to a desired location, such as when inserting or removing fasteners in generally inaccessible positions. For example, gears can be positioned in a horizontal, vertical, diagonal or staggered arrangement depending on the position of the fastener. Accordingly, the attachment including the bolting insert described herein should not be limited to that illustrated in the drawings or otherwise described herein. 
   Referring now to the adapter portion  102  and bolting insert portion  120  of the attachment  100  in accordance with the exemplary embodiment of the present invention shown in  FIGS. 2 ,  3 A- 3 B and  4 A- 4 B, once assembled, the bolting insert portion  120  may be removably inserted in the receptacle  104  of the adapter portion  102  such that the drive gear  126  is positioned over the channel  110  in the adapter portion  102 . The bolting insert portion  120  may then be secured to the adapter portion  102  with screws  140  (two of which are shown) that may extend through the cover  124  and the base  122  and into the threaded holes  112  of the adapter portion  102 . In another embodiment, the bolting insert portion  120  may be removably secured to adapter portion  102  through a snap and lock arrangement or any other arrangement suitable for removably securing the bolting insert portion  120 . Of course, it should be understood that bolting insert portion  120  and adapter portion  102  may be integral, although such a configuration may not be desirable in an embodiment wherein changing of worn gears is needed. 
   Once the adapter portion  102  and the bolting insert portion  120  are secured, and referring specifically to  FIG. 2 , a power tool  152  having a drive socket  150  attached to the drive mechanism  154  may be inserted in the opening  108  of the adapter  102  such that the drive socket  150  extends through the channel  110  of the adapter  102  and in contact with the drive gear  126 . The drive socket  150  may be a hexagonal drive socket that engages with the hexagonal mating surface  148  of the drive gear  126 , as shown in  FIGS. 4A and 4B . The adapter portion  102  may be rotated on the power tool  152  until suitable positioning of the attachment  100  is achieved for the specific application. The adapter portion  102  may then be secured to the power tool  152  with set screws  106 . In another embodiment, as described above, the adapter portion  102  may comprise threads in the base  107  to secure the adapter portion  102  to mating threads on the power tool. 
   Referring to  FIGS. 2 ,  4 A and  4 B, when the power tool  152  is actuated, the drive mechanism  154  and attached drive socket  150  rotate about a common axis of rotation  160 . Because the drive socket  150  is engaged with the drive gear  126  of the bolting insert portion  120 , the drive gear  126  also rotates about the axis of rotation  160 . At the engagement of the drive socket  150  with the drive gear  126 , the axis of rotation  160  defines a plane of rotation  162  in which the drive gear  126  rotates. The rotational motion of the drive gear  126  is then translated to the bolting gear  128  via the center gear  130 . The bolting gear  128 , and the particular socket insert  134  engaged therewith, rotate in the same direction as the drive mechanism  154  of the power tool  152  about a second (e.g. parallel) axis of rotation  164  that is offset from the axis of rotation  160  of the drive gear  126 . In an embodiment having an even number of gears, the power tool  152  would need to rotate opposite the desired rotation of the bolting gear  128  because immediately adjacent gears rotate in opposite directions. 
   While the bolting gear  128  rotates about a different axis of rotation  164  than the drive gear  126 , both the bolting gear and the drive gear rotate in the same plane  162 . Further, the socket insert  134  rotates about the same axis of rotation  164  as the bolting gear  128  and in a plane of rotation  166  that is parallel to the plane of rotation  162  of the bolting gear  128  and drive gear  126 . 
   Referring now to  FIG. 5 , the attachment  100  is shown in use. In the exemplary embodiment of  FIG. 5 , the attachment  100  is illustrated as being secured to a power tool  152  and near engagement with a fastener  116  partially secured between a vehicle door and a vehicle body. The orientation of the bolting insert  120  relative to the adapter  102  and power tool  152  allows the socket insert  134  to engage with the otherwise generally inaccessible fastener  116  without the power tool  152  adversely interacting with the surrounding structure. Once engaged, the power tool  152  is actuated, thereby causing rotation of the socket insert  134  and fastener  116 . The operator applies a force F to the power tool  152  to keep the socket insert  134  engaged with the fastener  116  as the fastener  116  is advanced toward the workpiece  50 . The direction of the force F is generally parallel to the axis of rotation  160  of the power tool  152 . The force F is transmitted to the adapter  102 , bolting insert  120 , socket insert  134 , and, ultimately, the fastener  116 . Because the socket insert  134  rotates in a plane  166  parallel to the plane of rotation  162  of the power tool, and about an axis of rotation  164  parallel to the axis of rotation  160  of the power tool, the force f exerted on the fastener  116  is substantially parallel to the force F exerted on the power tool  152 . Because a sturdier grip on the fastener  116  can be attained through the transfer of force the attachment  100  is less prone to slippage and stripping of the fastener  116  than the prior art attachment shown in  FIG. 1 . 
   Moreover, the tool attachment shown and described herein is versatile and may be configured for use in a variety of applications and may be adapted for attachment to power tools of various configurations. The tool attachment may also be configured for installing and removing a wide assortment of fasteners including bolts, nuts, screws, and the like. Further, the tool attachment can be constructed from inexpensive individual components that are readily available thus reducing the overall cost of the tool attachment and replacement parts. The design of the attachment facilitates the easy repair or replacement of component parts thereby reducing repair time and costs. The use of lightweight materials in the construction of the attachment can greatly reduce the overall weight of the attachment and minimizes the ergonomic burden on the operator. 
   While particular embodiments and aspects of the present invention have been illustrated and described, various other changes and modifications can be made without departing from the spirit and scope of the invention. Moreover, although various inventive aspects have been described, such aspects need not be utilized in combination. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.