Patent Publication Number: US-7900495-B2

Title: Powered conduit bender

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     There are no related applications. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a conduit bender and more particularly, to a powered conduit bender. 
     2. Background Art 
     Tubing, such as electrical conduit, is conventionally supplied as a straight, elongate tube. Prior to installation, it is often necessary to provide a bend in the conduit. This is often accomplished with a manually operated tool known as a conduit bender which provides a desired bend in the conduit without collapsing of the conduit walls. 
     A typical conduit bender includes a handle and a head. The head is of one piece construction including an arcuate shoe with a laterally concave groove for supporting the conduit. A hook is proximate one end of the shoe for engaging a conduit received in the channel. The handle is secured to the head and is generally positioned in a radial line relative to the arcuate shoe. The conduit rests on a support surface with the hook engaging the conduit. The handle is forced downwardly to roll the shoe onto the conduit with the hook pulling the conduit upwardly to form a bend. 
     Such a conduit bender requires the presence of a support surface for the conduit and the strength to force the handle to produce the bend. Also, it is necessary for the person using the conduit bender to frequently start and stop the bending operation to observe the bender relative to the conduit to see if the appropriate bending angle has been achieved. 
     Pending application Ser. No. 12/011,849, filed Jan. 30, 2008, and assigned to the Assignee of the present application, describes a powered conduit bender adapted to bend a single size conduit using a hand held, battery-powered tool. If required to bend different sizes of conduit, then the design disclosed therein requires a different tool for each size conduit. 
     The present invention is directed to further facilitating the operation of bending a conduit or similar tube. 
     SUMMARY OF THE INVENTION 
     In accordance with the invention, there is provided a portable, modular powered conduit bending tool which can be used with one handed operation. 
     In accordance with a first aspect of the invention, there is disclosed a powered conduit bending tool comprising a portable drive housing including a handle and having a powered drive gear. A bracket is secured to the housing defining a pivot connection spaced from the drive gear. A guide is operatively secured to the housing. A platform is pivotally connected to the bracket at the pivot connection and includes a driven gear operatively engaging the drive gear to controllably pivot the platform. A shoe is removably mountable to the platform and comprises a first bender defining a downwardly opening arcuate channel selectively positionable proximate the guide. A hook is proximate one end of the bender for engaging a conduit received in the channel. In use, the guide supports a conduit engaged by the hook and pivotal movement of the shoe driven by the platform deforms the conduit as it passes by the guide. 
     It is a feature of the invention that the driven gear comprises gear teeth disposed in a path adjacent the arcuate channel. 
     It is another feature of the invention that the driven gear comprises an arcuate rack secured to the platform. 
     It is a further feature of the invention that the platform comprises a pivot opening receiving a bolt connected to the bracket at the pivot connection and a guide pin is spaced from the pivot opening a select distance. 
     In one embodiment of the invention the shoe comprises a pipe threadably connected to the first bender and the pipe includes a pair of spaced apart openings spaced apart the select amount. One of the openings receives the bolt and the other opening receives the guide pin. The shoe may comprise a handle at a distal end of the pipe. 
     In another embodiment of the invention, the shoe comprises a pipe threadably connected at one end to the first bender and at a second end to a second bender of a different size from the first bender. The pipe includes a center opening, a first opening associated with the first bender and spaced from the center opening by the select amount, and a second opening associated with the second bender and spaced from the center opening by the select amount. The center opening receives the bolt and one of the first and second openings receives the guide pin dependent on which of the first and second benders is to be used. 
     It is still another feature of the invention that the guide comprises a spool. The spool may comprise a self-centering spool. The spool may be mounted to a shaft on the bracket with a seat spring self-centering the spool. 
     It is still a further feature of the invention that a battery is removably connected to the handle to provide a battery operated tool. 
     There is disclosed in accordance with another aspect of the invention a powered conduit bending tool comprising a portable drive housing including a handle and having a powered drive gear. A bracket is secured to the housing defining a pivot connection spaced from the drive gear. The bracket includes a shaft supporting a self-centering guide spool. A platform is pivotably connected to the bracket at the pivot connection and includes a driven gear operatively engaging the drive gear to controllably pivot the platform. A shoe is mounted to the platform and comprises a bender defining a downwardly opening arcuate channel selectively positionable proximate the guide. A hook is proximate one end of the bender for engaging a conduit received in the channel. In use, the guide spool is self-centered on the shaft to support conduit that is engaged by the hook and pivotal movement of the shoe driven by the platform deforms the conduit as it passes by the guide spool. 
     It is a feature of the invention that the driven gear comprises gear teeth disposed in a path adjacent the shoe. 
     It is another feature of the invention that the driven gear comprises an arcuate rack. 
     It is a further feature of the invention to provide a seat spring on the shaft between the bracket and the guide spool. 
     It is yet another feature of the invention that the guide spool comprises a roller. 
     It is an additional feature of the invention that a battery is removably connected to the handle to provide a battery operated tool. 
     It is still a further feature of the invention that the platform comprises a pivot opening receiving a bolt connected to the bracket at the pivot connection and a guide pin is spaced from the pivot opening a select distance. 
     It is still a further feature of the invention that the shoe comprises a pipe threadably connected to the bender and the pipe includes a pair of openings spaced apart the select amount. One of the openings receives the bolt and the other opening receives the guide pin. 
     Further features and advantages of the invention will be readily apparent from the specification and from the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front elevation view of a powered conduit bender in accordance with the invention including a dual bender shoe; 
         FIG. 2  is a front elevation view, similar to  FIG. 1 , showing the powered conduit bender configured to bend conduit of a first size; 
         FIG. 3  is a front elevation view, similar to  FIG. 1 , showing the powered conduit bender configured to bend conduit of a second size; 
         FIG. 4  is a perspective view of the powered conduit bender in accordance with the invention with the shoe removed; 
         FIG. 5  is a front elevation view of the dual bender shoe of  FIG. 1 ; 
         FIG. 6  is a front elevation view of a single bender shoe for a third size conduit; 
         FIG. 7  is a front elevation view of a single bender shoe for a fourth size conduit; and 
         FIG. 8  is a partial, perspective view, illustrating a self-centering guide spool of the powered conduit bender of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to  FIG. 1 , a powered conduit bending tool  10  in accordance with the invention is illustrated. The powered conduit bending tool  10  comprises a battery powered device which enables a user using only one hand to accurately and simply bend a conduit to a desired angle. Moreover, the powered conduit bending tool  10  is part of a modular system adaptable to bend different sizes and types of conduit by enabling easy replacement of shoe sizes and automatic guide adjustment. 
     The powered conduit bending tool  10  includes a housing  12  including a gripping handle  14 . The housing  12  is generally similar to a conventional portable tool, such as a drill. A battery  16  is removably mounted to the housing  12 , in a conventional manner, and powers a battery operated powered drive having a drive gear  18  (shown in phantom). The drive in the housing  12  converts electrical power to drive the drive gear  18  in a conventional manner using a switch  20 . For example, the drive may be generally similar to a conventional cordless drill, except that a chuck is replaced with the drive gear  18 . Alternatively, the drive could be operated off of a 120 Vac supply and include a power cord, as will be apparent. The switch  20  is movable between a center off position and up and down positions for forward and reverse rotational movement of the drive gear  18 , as described below. 
     The basic operation of the powered conduit bending tool  10  may be as described in pending application Ser. No. 12/011,849, filed Jan. 30, 2008, and assigned to the Assignee of the present application, the specification of which is incorporated by reference herein. 
     Referring also to  FIGS. 2 and 4 , a generally triangular bracket  22  is secured to the housing  12 . The bracket  22  includes a generally vertical leg  24 , see  FIG. 2 , extending upwardly from the housing  12  and connected to a generally horizontal leg  26 . Opposite ends of the vertical leg  24  and the horizontal leg  26  are connected to a generally diagonal leg  28  to provide the generally triangular configuration. The vertical leg  24  and the diagonal leg  28  meet at a top corner  27  which includes a threaded opening (not shown) to define a pivot connection  30  threadably receiving a T-shaped bolt  32 , as is apparent. The pivot connection  30  is spaced from the drive gear  18 . The horizontal bar  26  and the diagonal bar  28  meet at a side corner  29  which includes an opening  34 , see  FIG. 4 , for receiving a conduit guide  36 , see  FIG. 1 . 
     Referring to  FIG. 8 , the conduit guide  36  comprises a roller in the form of a guide spool  38  received on a shaft  40 . The guide spool  38  includes a concave guide surface  39  for engaging a conduit. A first end  42  of the shaft  40  is enlarged and is positioned on a back side of the bracket  22  so the central part of the shaft  40  extends through the opening  34  and receives the guide spool  38 . A seat spring  44  on the shaft  40  is between the guide spool  38  and the bracket  22 . A nut  46  is threaded to an opposite end of the shaft  40  to retain the guide spool  38  on the shaft  40 . The nut  46  includes an enlarged head  48  and a narrowed neck  50 . The neck  50  receives a notch  52  in a mounting bracket  54 , see  FIG. 1 , pivotally connected to the T-bolt  32 . The notch  52  allows the mounting bracket  54  to be moved out of position, as shown in  FIG. 1 , when necessary. Otherwise, the mounting bracket  54  is shown captured in  FIG. 2 . The mounting bracket  54  distributes pressure away from the pivot connection  30 . 
     Referring to  FIG. 4 , a platform  56  is pivotally connected to the bracket  22  at the pivot connection  30 . The platform  56  comprises a generally triangular or pie shaped metal plate  58  having a generally triangular opening  60  at one side. At another side is a generally triangular support  62  which may be formed of aluminum or the like and is secured to the plate  58 . An opening  64  passes through the support  62  at a corner  65  of the plate  58 . The opening  64  is coaxial with the pivot connection  30  for receiving the T-bolt  32  to pivotally connect the platform  56  to the bracket  22 . An arcuate rack  66  is secured to the plate  58  in a radius about the opening  64  using fasteners  68 . The arcuate rack  66  includes a toothed outer edge  70  to define a driven gear which engages the drive gear  18 , see  FIG. 1 . As is apparent, rotation of the drive gear  18  drives the driven gear  70  to pivot the platform  56  about the pivot connection  30 . 
     A stabilizing bracket  72  is mounted atop the housing  12  and includes a pair of threaded bolts  74  which can be selectively positioned to bear on the arcuate rack  66 , see  FIG. 8 , to stabilize the platform  56 . 
     The T-bolt  32  comprises a shaft  76  and a cross bar  78 . A distal end (not shown) of the shaft  76  is threaded to be selectively threadably secured to the bracket  22 , as is apparent. A guide pin  80  extends upwardly from the platform  56  proximate one edge of the support  62  and spaced a select amount from the T-bolt shaft  76 , as is apparent. 
     In accordance with the invention, the powered conduit bending tool  10  is adapted to removably mount one of different available shoes to allow the conduit bending tool  10  to be used to bend different size conduits by simply replacing the shoe. Moreover, the guide  36  is self-centering, as described below, to accommodate different size conduit. 
     In an illustrative embodiment of the invention, the powered conduit bender can be used with a dual bender shoe  100 , see  FIG. 5 , including a first bender  102  for bending ½″ EMT conduit and a second bender  104  for bending ¾″ EMT or ½″ rigid conduit. A first single bender shoe  200 , see  FIG. 6 , is adapted for bending 1″ EMT or ¾″ rigid conduit using a bender  202 . Finally, a second single bender shoe  300 , see  FIG. 7 , includes a bender  302  for bending 1¼″ EMT and 1″ rigid conduit. Each of the benders  102 ,  104 ,  202 , and  302  are of conventional construction and comprise commercially available manually operated conduit benders that normally mount to a pipe to manually bend conduit, as is well known. Only the second bender  104  is described in detail herein, the others being of similar construction, albeit of different size. Other examples of conduit benders are shown in U.S. Pat. Nos. 4,452,064 and 5,927,141. 
     The second bender  104 , see  FIG. 8 , includes an arcuate body  106  defining a radially downwardly opening arcuate channel  108  of a cross section to receive a conduit. The channel  108  is concave and the body  106  defines a convex arc, as is known. A hook  110  is provided at one end of the arcuate body  106 , see  FIG. 5 . A leg  112  connects opposite ends of the arcuate body  106  and includes a central collar  114  having a through opening (not shown). A female threaded adapter  116  is provided in the arcuate body  106  axially aligned with the collar  114 . In a conventional, manual operation, a pipe is passed through the collar  114  and threaded into the adapter  116  in use. In accordance with the invention, a smaller pipe  118  is used having opposite first and second threaded ends  120  and  122 , respectively. A center through opening  124  is provided through the pipe  118  approximately midway between the threaded ends  120  and  122 . A first opening  126 , associated with the first bender  102 , is provided between the center opening  124  and the first threaded end  120 . A second opening  128  is provided between the center opening  124  and the second threaded end  122 . Spacing between the center opening  124  and each of the first opening  126  and second opening  128  is equivalent to the select spacing between the T-bar shaft  76  and guide pin  80 , see  FIG. 4 , discussed above. 
     In order to mount the shoe  100  to the tool  10 , the T-bolt  32  is removed by turning the crossbar  78  to unthread the connection. Thereafter, the shoe  100  is placed atop the platform  56 . In a first configuration, as shown in  FIGS. 1 and 2 , to use the second bender  104 , the shoe  100  is placed on the platform  56  so that the guide pin  80  passes through the second opening  128 . Thereafter, the T-bar shaft  76 , shown in  FIG. 4 , is inserted through the center opening  124  and threaded into the pivot connection  30  and tightened to secure the first shoe  100  to the rotary platform  56 . The pipe  118  also includes a hub  130  surrounding the center opening  124  to provide suitable positioning for receiving the T-bolt  32 . As is apparent, the support  62  provides a flat surface for seating the shoe  100  on the platform  56 . The mounting bracket  54  can then be also placed in position, as shown in  FIG. 2 . In this configuration, the powered conduit bending tool  10  is used to bend a conduit C 1 , see  FIG. 2 , in the form of ¾″ EMT or ½″ rigid conduit. 
     If the dual bender shoe  100  is to be used with ½″ EMT conduit, then the first shoe  100  is removed, reversing the procedure discussed above. The shoe  100  is then rotated 180° so that the first bender  102  is in the operative position for bending ½″ EMT conduit C 2 , as shown in  FIG. 3 . In this configuration, the guide pin  80  is received in the first opening  126 , as is shown. 
     Referring to  FIG. 6 , the second shoe  200  is illustrated. The second shoe  200  includes the third bender  202  of a size to bend 1″ EMT or ¾″ rigid conduit. A pipe  204  includes a threaded end  206  and a distal end  208  connected to a carrying handle  210 . A first opening  212  is positioned at approximately a midpoint of the pipe  204  and includes a surrounding hub  214 . A second opening  216  is provided between the first opening  212  and the threaded end  206 . As above, spacing between the openings  212  and  216  is identical to spacing between the T-bar shaft  76  and the guide pin  80 . The pipe  204  passes through a collar  218  on the third bender  202  with the threaded end  206  threaded into an adapter  220 . The second shoe  200  can be used by removing the first shoe  100  from the platform  56  and positioning the shoe  200  with the second opening  216  receiving the guide pin  80  and the T-bar shaft  76  inserted through the first opening  212  and threaded into the pivot connection  30 . 
     Referring to  FIG. 7 , the third shoe  300  includes the fourth bender  302  adapted for use with 1¼″ EMT and 1″ rigid conduit. A pipe  304  includes a threaded end  306  and an opposite end  308  connected to a carrying handle  310 . A first opening  312  is provided proximate the distal end  308 . A second opening  314  is provided midway between the first opening  312  and the threaded end  306 . The pipe  304  passes through a collar  316  on the fourth bender  302  with the threaded end  306  threaded into an adapter  318 . Spacing between the openings  312  and  314  is equal to spacing between the T-bar shaft  76  and the guide pin  80 , as discussed above. As is apparent, relative positions of the openings  312  and  314  is positioned so that the bender is in an appropriate radial position relative to the pivot connection  30  to properly bend a 1¼″ EMT or 1″ rigid conduit. 
     The use of the powered conduit bending tool  10  is generally consistent with that described in the co-pending application incorporated by reference herein. The operation is described herein with respect to the use of the second bender  104 , as shown in  FIGS. 1 and 2  in the operative position. The platform  56  and thus the second bender  104  are initially pivoted away from the drive gear  18  so that it does not engage the arcuate rack  66  and the second bender  104  is freely rotatable. The conduit C 1 , which is initially straight, is positioned in the second bender  104  in a conventional manner with the hook  110  engaging the conduit C 1 . With the conduit C 1  seated in the hook  110 , the platform  56  can be released and it pivots about the pivot connection  30  until the conduit C 1  engages the guide  36 . Particularly, the conduit C 1  would be seated in the spool concave guide surface  39 , which has a curved cross section. As is apparent, with a different size bender, and different size conduit, the relative position of the conduit relative to the platform  56  can vary. The self-centering of the guide  36 , provided by the spring  44 , causes the axial position of the guide spool  38  to be self-adjusted on the shaft  40  to self-center the guide  36  according to the position of the conduit C 1  to be bent. 
     Incident to the conduit C 1  engaging the guide  36 , the arcuate rack  66  engages the drive gear  18 . The user can then actuate the switch  20  in a forward direction to begin rotating the platform  56  and thus second bender  104  in a counter clockwise direction, relative to the orientation illustrated in  FIG. 2 . The hook  110  maintains the conduit C 1  in the second bender  104 . The guide  36  acts as a support surface which supports and guides the conduit C 1 . The bending force exerted on the second bender  104  by the powered drive is transmitted to the conduit C 1  by the hook  110  which bends the conduit C 1  around the second bender  104  in a conventional manner, albeit using a battery-operated tool rather than manual bending.  FIG. 2  illustrates the conduit C 1  bent with the arcuate rack  66  in a near fully extended position to provide approximately a 90° bend. To release the conduit C 1 , the switch  20  is moved to the reverse position to return the rotary platform  56  to a neutral position so that the conduit C 1  can be simply removed. 
     Operation of the tool  10  using the other shoes is similar to that discussed relative to the second bender  104 . 
     Although the powered conduit bending tool  10  is described in connection with bending conduit, the device can be more generally thought of as a powered tube bender for bending any thin walled tube intended to be formed in this manner. Thus, use of the term conduit herein is intended to refer to any such tubing element, as will be apparent. 
     In operating the powered conduit bender  10 , the housing  12  can be held up so that it is easily visible to the user to determine if the proper angle has been satisfied. As such, the benders  102 ,  104 ,  202  and  302  may include conventional markers or other indicators indicating the angle. Moreover, the gearing relationship provided between the drive gear  18  and the driven arcuate rack  66  is such that the drive can be started and stopped as necessary to provide the desired bend. 
     Thus, in accordance with their invention, there is provided a portable, powered conduit bender of the size of a conventional portable power tool enabling conduits of different sizes to be bent with a one handed operation.