Patent Publication Number: US-6209371-B1

Title: Pipe bender angle indicator

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Not Applicable 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable. 
     BACKGROUND OF THE INVENTION 
     This invention relates to pipe benders, and, in particular, to an angle indicator for a pipe bender which can be mounted to the handle of a pipe bender. 
     Pipe benders have long been used by electricians to bend piping through which electrical wires pass. Such pipe benders, as is known, include a curved bending head or shoe which receives the pipe to be bent, and a handle which can be grasped by the electrician. To bend the pipe, the electrician simply places the pipe in the head, and pivots the head using the handle to bend the pipe. The pipe is bent around the curvature of the shoe until the desired angle of bend is reached. 
     When an electrician bends a pipe, he tries to achieve a particular angle, typically 45° or 90°. However, other size angles are often required. If a pipe is not bent to the desired angle (i.e., if the angle is overshot or undershot), then the pipe will not lay were desired, and the pipe may not lay flush against a surface, for example. This can impact wall construction in a building. It is thus desirable to enable electrician to determine as accurately as possible when a desired angle is reached. 
     Many different angle indicators have been developed. Many are incorporated into the head or shoe of the pipe bender. This obviously requires that a special mold be made for the pipe bender head, and thus increases the cost of the pipe bender. Further, when the angle indicator is built into the head, if the indicator should break, it cannot be replaced without replacing the entire head. For these reasons, pipe bender heads with angle indicators have not been well accepted by the industry. 
     Other angle indicators have been developed which clip to the handle of the pipe bender. These indicators are large, and thus difficult to use, or electric, and hence expensive. 
     BRIEF SUMMARY OF THE INVENTION 
     Briefly stated, an angle indicator of the present invention is intended for use with a pipe bender and is adapted to be removably mounted to the handle of the pipe bender. The angle indicator includes a mount adapted to mount the angle indicator to a handle of the pipe bender. Preferable, the mount is in the form of a spring clip, so that the angle indicator can simply be pressed onto the handle of the pipe bender and pulled off after the pipe has been bent. 
     A plate extends from the mount and first and second wheels are rotatably mounted to the plate. The second plate is smaller than the first plate and is mounted concentrically with the first plate. The first plate includes a plurality angle indicating marks evenly spaced about a periphery of the first wheel. The second plate includes a mark at a periphery of the second wheel. The second wheel mark is selectively alignable with one of the angle indicating marks of the first wheel. 
     A bubble level is mounted on the second wheel. The bubble level can either be a straight or a curved level. If it is a straight level, it is preferably extends across the second wheel in a line perpendicular to the mark on the second wheel. If the bubble level is curved, it can be mounted to the periphery of the second wheel, or along the edge of the second wheel. 
     A lock is provided to hold the first and second wheels in desired rotational positions. The angle indicator includes a bolt having a threaded shaft and a head at an end of the shaft. The threaded shaft is received in the plate and defines an axle about which the first and second wheels rotate. In the disclosed embodiment, the shaft extends through the plate, and a nut is received on the shaft on a back side of the plate. The bolt defines the lock. By tightening the bolt down, unwanted movement of the wheels are prevented and when the bolt is loosened, the wheels can be moved relative to each other. 
     The angle indicator is preferably also provided with a second lock, independent of the first lock, to locks the first wheel in place relative to the plate. The second lock includes a threaded shaft with an enlarged head on the shaft. The shaft passes through the plate adjacent the first wheel such that the head overlaps the first wheel. A nut is received on the shaft on the back side of the plate. When the second lock is tightened down, the head frictionally engages the first wheel to prevent unwanted movement of the first wheel relative to the plate. 
     In a second embodiment, the angle indicator includes only one wheel, on which a curved bubble level is mounted. The wheel includes a plurality of angle indicators at the periphery of the wheel, and the bubble level can be mounted on either side of the markings. 
     In a third embodiment, the lock for the for one or both of the wheels of the first embodiment or for the one wheel in the second embodiment, can comprise a ball and detent. In this situation, the axle about which the wheels rotate would be provided with a spring biased ball which radiates from the axle, and the wheel would be provided with detents (or similar structure) with which the ball would interact to hold the wheel in a desired position. 
     The advantage of either embodiment, is that the angle indicator allows for zeroing of the indicator. Hence, the indicator can be used with almost every pipe bender, no matter the angle between the pipe bender handle and the ground prior to bending of the pipe. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     FIG. 1 is an elevational view of a pipe bender with an angle indicator of the present invention mounted to a handle of the pipe bender; 
     FIG. 2 is a front elevational view of the angle indicator; 
     FIG. 3 is a end elevational view of the angle indicator; 
     FIG. 4 is an exploded view of the angle indicator; 
     FIG. 5 is a front elevational view of an alternative embodiment for the angle indicator; and 
     FIG. 6 is a cross-sectional view of a third embodiment of the angle indicator. 
    
    
     Corresponding reference numerals will be used throughout the several figures of the drawings. 
     DETAILED DESCRIPTION OF THE INVENTION 
     The following detailed description illustrates the invention by way of example and not by way of limitation. This description will clearly enable one skilled in the art to make and use the invention, and describes several embodiments, adaptations, variations, alternatives and uses of the invention, including what I presently believe is the best mode of carrying out the invention. 
     A typical pipe bender  1  is shown in FIG.  3 . The pipe bender  1  includes a head  3  having a curved shoe  5  and a stem  7  extending up from the shoe  5 . A handle  9  is removably received in the stem  7  and can be grasped by an electrician to pivot the head  3  to bend a pipe as is known. The head  3  does not form any part of the present invention, and can be a conventional head. Not all pipe benders are made the same. Thus, the stem  7 , and hence the handle  9 , may not always extend from the shoe  5  at the same angle. Stated differently, the handle  9  of different pipe benders can form different angles with the ground when the pipe is received in the shoe, but before the pipe is bent. 
     An angle indicator  11  of the present invention is shown mounted to the handle  9 . The angle indicator  11  is shown in more detail in FIGS. 2-4. The angle indicator includes a backing plate  13  extending from a mounting clip  15 . The clip  15  is shown to be a spring clip which spreads apart as it is pressed onto the handle  9 , and then springs back to a normal position to grip the handle  9  to hold the indicator  11  in place on the handle  9 . The clip  15  defines an arc which is slightly more than 180°, so that it can be pressed onto and grasp the handle  9  and so that it can be easily removed from the handle simply by pulling. Any other conventional type of mounting bracket could be used to removably secure the indicator  11  to the handle. For example, the mounting bracket could include a pair of spaced apart legs which are tightened together using a screw. Or, straps with Velcro could be used to mount the plate  13 , and hence the indicator  11 , to the handle  9 . Alternatively, the clip  15  could include magnets to magnetically mount the indicator  11  to the handle  9 . 
     The backing plate  13  includes a pair of holes,  17  and  19 . A first wheel  21  and a second wheel  23  are rotatably mounted to the backing plate  13 . The two wheels are mounted to the backing plate  13  with the first wheel adjacent the plate  13 , and the second wheel  23  on top of the first wheel  21 . As shown, the first and second wheels  21  and  23  each have a central hole  25  and  27 , respectively, and a screw  29  passes through the central holes of the two wheels and through the hole  17  in the plate  13 . A nut  31  on the back side of the plate  13  is used to tighten the screw  29  in place. As can be appreciated, the screw  29  defines an axle about which both wheels  21  and  23  rotate. Although a screw is provided, the second wheel  23  can be formed to include a threaded shaft extending from the back surface of the wheel to pass through the first wheel  21  and the plate  13  to receive the nut  31 . 
     Although the screw is shown held in place by the nut  31 , the hole  17  into which the screw  29  passes could be threaded, and the screw could be screwed into the plate  13 . This would eliminate the need for the nut  31 . 
     The first wheel  21  includes a plurality of angle markings  33  extending around the periphery of the wheel. The first angle marking is indicated to be at 0°. The angle markings  33  are shown to extend a full 1800 around the wheel  21  with larger markings showing increments of 15° and smaller markings showing increments of 5°. 
     The second wheel  23  is smaller in diameter than the first wheel  21  and includes a single indicating line  37 . The second wheel  23  is sized so that the angle markings of the first wheel  21  are visible when the angle indicator  11  is assembled, as seen in FIGS. 1 and 2. A bubble or spirit level  39  is mounted to the second wheel  23 . As shown, the level  39  extends across the diameter of the second wheel  23 . Also, the level  39  is shown mounted to a spacer  41 , which in turn, is mounted to the second wheel. The spacer  41  allows for clearance for the head of the screw  29 . As can be seen, the bubble level is shown to be a straight level, and extends generally perpendicularly to the line  37 . 
     A second lock screw  43  is received in the second hole  19  in the plate  13 . The hole  19  is positioned, as seen in FIG. 2, so that the head  45  of the screw  43  overlaps the edge of the first wheel  21 . The hole  19  can be a threaded hole which receives the screw  43 . Alternatively, a nut can be received on the shaft of the screw  43  on the back side of the plate  13 . 
     The first wheel  21  is directly against the plate  13  and the second wheel  23  is directly against the first wheel  21 . As can be appreciated, when the nut  31  is tightened against the back surface of the plate  13 , the two wheels are fixed in position, and can not be readily moved relative to each other. When the nut  31  is loosened, the two wheels can move relative to each other. The bolt  29  and nut  31  thus act as a lock to lock the wheels in position, as will be described below. 
     In operation, the angle indicator  11  is clipped to the handle  9  of the pipe bender  1 . As noted above, with the spring clip  15 , this is accomplished simply by pressing the mounting clip over the handle  9 . The nut  31  which is threaded onto the shaft  29  and the lock screw  43  are loosened so that both the first wheel  21  and the second wheel  23  can rotate about the screw  29 . The two wheels are not connected to each other and hence can rotate relative to each other. 
     After the pipe bender has been applied to the pipe, the first step is to zero the angle indicator. This is accomplished by rotating the second wheel until the bubble B in the level  39  is centered to indicate that the level  39  is horizontal or parallel to the ground. The first wheel is then rotated until its zero mark lines up with the line  37  on the second wheel  23 . The zeroing operation can also be done by first lining up the zero mark on the first wheel with the line  37  on the second wheel  23  and then rotating the two wheels together until the bubble level indicates that the level is horizontal. The lock screw  43  is then tightened to lock the first wheel  21  in position. 
     The second wheel  23  is then rotated to line up its mark  37  with a desired degree mark  33  on the first wheel. Thus, for example, if a 25° angle is desired, the second wheel is rotated until the mark  37  lines up with the first wheel mark  33  corresponding to 25°. The nut  31  is rotated to tightened the screw  29  down to lock the second wheel  23  in position. 
     The lock screw  43  provide a separate lock for the first wheel so that the first wheel can be locked in position, and the second wheel can be rotated without fear of rotating the first wheel. However, because the second lock (i.e., the screw  29  and nut  31 ) holds both the first and second wheels in their desired positions, the lock screw  43  could be eliminated if desired. 
     Once the angle has been indicated, the electrician bends the pipe in the usual manner, keeping an eye on the level. When the level bubble is centered, to indicate that the level is horizontal, the desired bend for the pipe is reached, and the electrician can stop the bending process. 
     Although the angle indicator  11  is shown with a straight bubble level  39 , a curved bubble level could be provided as well. The operation of the angle indicator would be the same. 
     A second embodiment of the angle indicator is shown in FIG.  5 . The angle indicator  11 ′ includes a mounting clip  15 ′ and plate  13 ′ which are identical to the clip  15  and plate  13  of the indicator  11 . However, rather than having two wheels, the angle indicator  11 ′ includes only one wheel  21 ′. A plurality of angle indicating marks  33 ′ are formed about the periphery of the wheel  21 ′. The marks  33 ′ are shown to extend about 180″ around the wheel, but could extend further if desired. A curved bubble level  39 ′ is mounted to the wheel  21 ′ inside of the marks  33 ′. Alternatively, the bubble level  39 ′ could be mounted to the edge of the wheel  21 ′. The indicator  11 ′ also includes a lock  43 ′ identical to the lock  43  of the indicator  11 . 
     In use, after the indicator  11 ′ is clipped to the handle, the lock  43 ′ is loosened and the wheel  21 ′ is rotated until the bubble B is centered in the level  39 ′, as shown in FIG.  5 . This zeros the indicator and the wheel  21 ′ can then be locked in place by tightening the screw  43 ′. The pipe is bent until the bubble lines up with the angle marking  33 ′ corresponding to the angle of the desired bend. In the indicator  11 ′, because the angle markings  33 ′ are on the wheel  21 ′, the mark  33   a  in the center of the markings will always correspond to 0°. As with the indicator  11 , the markings  33 ′ are spaced apart by 5°, with larger marks every 15°. 
     In the indicator  11 ′, the angle markings  33 ′ are on the wheel  21 ′. Alternatively, the markings  33 ′ could be on the backing  13 ′ adjacent the wheel. In this instance, the pipe bender must note which marking  33 ′ the bubble B lined up with when the indicator  11 ′ was zeroed. From that point, knowing that the markings  33 ′ are separated by 5°, for example, the pipe bender can determine which marking the bubble B needs to line up with to arrive at the desired angle. 
     The angle indicator is designed to be small so that it can easily fit in a shirt pocket, tool belt, tool box, etc. For example, the first and second wheels can have diameters of about 2″ and 1½ respectively. With wheels this size, the plate would be about 2″ across and 2″ tall, and the clip would be about 2″ long. The indicator would have a height, from the bottom of the clip to the top of the plate of about 3″. The indicator could be made smaller is smaller wheels were used. 
     The stems  7  of commercially pipe bender heads do not always extend up at the same angle. Thus, when a pipe bender is applied to a pipe, the handles from different heads will extend at different angles relative to the ground. The ability to zero the angle indicator  1  allows the angle indicator to be used with many different heads, and the angle of attachment of the handle  9  to the head  3  does not matter. 
     In another variation, at least the lock for the second wheel  23  of the indicator  11 ″ could be replaced with a ball and detent or similar means, as seen in FIG.  6 . In such an instance, for example, the screw  29  could be replaced with a post  29 ″ which would serve as the axle for the wheels  21 ″ and  23 ″. The post  29 ″ would include a short bore  51 ″ into which a spring  53 ″ and a ball  55 ″ are placed, such that the spring biases the ball outwardly. The edge of the central opening  25 ″ of wheel  23 ″ would then be provided with a series of spaced apart detents  57 ″. The spring biased ball  55 ″ would interact with the detents  57 ″ of the wheel to hold the wheel in the desired position. As can be appreciated, a lock could be provided for the wheel  21  or the wheel  21 ′ of indicator  11 ′. The ball and detent could also be replaced with a short, but flexible finger extending from the post. The wheel(s) would be provided with grooves on the edge of their central openings. The finger would interact with the groove to hold the wheel in a desired position. Although the springs  53 ″ and balls  55 ″ are shown to be placed in the post  29 ″ with the detent  57 ″ in the wheels, the balls and detents could be reversed: the spring and balls could be received in the wheels and the detents could be formed about the post  29 ″. 
     As can be appreciated, I have disclosed an angle indicator that has the advantage of being usable with any pipe bender, by merely zeroing the indicator for the particular pipe bender. In fact, once the angle indicator has been zeroed for use with a particular pipe bender, it need not be zeroed again. However, it would be advisable to periodically check the zeroing of the indicator to ensure that the wheel  23  has not moved. Additionally, because the indicator has the ability to dial in a desired angle, the angle of a pre-bent pipe can be duplicated without the need for knowing the angle of the bend in that pipe. The pipe bender, with the indicator thereon, is applied to the pre-bent pipe, and the wheel  23  (or  21 ′ or  23 ″) is rotated until the bubble is level. This will dial in the angle of the pre-bent pipe. Then, with the angle dialed in, the bender can be used, as described above, to form substantially identical bends in straight pipe. This bend can then be duplicated numerous times, without the need to reset the indicator. 
     As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. For example, the screw  29  can be replaced with a simple axle that is headed over on opposite sides to hold the two wheels  21  and  23  to the plate  13  and to allow the two wheels to rotate relative to each other. The angle indicator could be supplied with a second lock screw, similar to the lock screw  43 , which would include a finger which would press down on the second wheel when the screw is tightened to lock the second plate in the desired position. Alternatively, the first wheel  21  can be provided with an arced slot through which a second bolt could extend. This second bolt would be the second lock which locks the second wheel in place. Alternatively, spring clips can be provided for one or both of the wheels which frictionally engage the wheels to hold them in the desired position. All that is required is that the two wheels  21  and  23  (of indicator  11 ) be able to rotate relative to each other, and that there be a locking mechanism for the two wheels of the indicator  11  or of the one wheel  21 ′ of the indicator  11 ′ so that the wheels can be secured in desired positions. These examples are merely illustrative.