Patent Application
20240351086
This application claims benefit to Indian Provisional Application No. 202321028482 filed on Apr. 19, 2023, the contents of which are incorporated by reference in its entirety.
The present disclosure relates to a hand-held conduit bending tool having features which increase strength, thereby resulting in higher resistance against crack formation when the conduit bending tool falls under gravity.
Hand-held conduit bending tools for bending electrical conduits are known, and usually include a one-piece body that has an elongated curved bender head at its bottom, a hook at its front end, and an upwardly projecting handle receptacle in which a shaft-like handle is removably receivable. A foot pedal is provided at the rear of the bender head, and the user can step onto the foot pedal. The bender head has a curved channel therein in which the conduit is seated and is bent during a bending operation. The hook is engaged under a length of conduit to be bent, which is held against a floor or other supporting surface, and a bending force is exerted upon the handle and the foot pedal, transmitted to the conduit by means of the hook, and curves the conduit around the bender head. Examples of such conduit bending tools are provided in U.S. Pat. No. 4,622,837 and in United States Publication Nos. 2003/0233859, 2004/0182129, and 2017/0274437.
The organization and manner of the structure and operation of the disclosed embodiments, together with further objects and advantages thereof, may best be understood by reference to the following description, taken in connection with the accompanying drawings, which are not necessarily drawn to scale, wherein like reference numerals identify like elements in which:
While the disclosure may be susceptible to embodiment in different forms, there is shown in the drawings, and herein will be described in detail, a specific embodiment with the understanding that the present disclosure is to be considered an exemplification of the principles of the disclosure, and is not intended to limit the disclosure to that as illustrated and described herein. Therefore, unless otherwise noted, features disclosed herein may be combined together to form additional combinations that were not otherwise shown for purposes of brevity. It will be further appreciated that in some embodiments, one or more elements illustrated by way of example in a drawing(s) may be eliminated and/or substituted with alternative elements within the scope of the disclosure.
A hand-held conduit bending tool 20 includes a bender head 22 and an elongated handle 24, see
The handle 24 has a free end and a connected end and the bender head 22 is disposed on the connected end of the handle 24. The handle 24 may be constructed from plastic, or metal, such as tubular steel, or other suitable material. The handle 24 may have a grip, such as for example a rubber molding, or knurling provided on the free end to assist in the user grip on the handle 24. For convenience in explanation only, terms such as upper, lower are used, but do not indicate that these directions are required during use of the conduit bending tool 20.
The material of which the bender head 22 is formed is brittle. The bender head 22 may be formed of high strength, nonferrous, light weight material with low elongation, and may be formed of Aluminum, and specifically Aluminum A-380. Aluminum A-380 is desirable since it has a lower weight and lower cost, but it is brittle (brittle being defined as materials having between 1% and 6% elongation). In a preferred embodiment, the bender head 22 is formed of a brittle material having 2.5% to 3.5% elongation. Brittle materials perform better when a compressive load is placed thereon than when a tensile load is applied. The bender head 22 may be formed using heat treating. In an embodiment, the hand-held conduit bending tool 20 has a weight of approximately five to six pounds, with the bender head 22 being approximately two pounds. When the conduit bending tool 20 falls, the conduit bending tool 20 falls under its own weight by gravity onto the bender head 22 as shown in
The bender head 22 includes a body portion 38 having a front end 40, an opposite rear end 42, upper and lower surfaces 44, 46 extending between the front and rear ends 40, 42, first and second side surfaces 48, 50 extending between the front and rear ends 40, 42 and the upper and lower surfaces 44, 46, and a hook portion 52 extending from the front end 40 of the body portion 38. The upper surface 44 may be formed of an upper curved bar 54, and the lower surface 46 may be formed of a lower curved bar 56, which are connected together by a plurality of struts 58 which define windows. Alternatively, the body portion 38 may be a solid part such that the windows are eliminated. A longitudinal centerline of the body portion 38 extends between the front and rear ends 40, 42.
The body portion 38 has first and second downwardly facing channels 60, 62, see
The first channel 60 includes opposite first and second side walls 64, 66 which are connected by a base wall 68. A longitudinal centerline extends from the front end of the first channel 60 to the rear end of the first channel 60 through the midpoint of the base wall 68. The first side wall 64 terminates in a first lower wall surface 72, and the second side wall 66 terminates in a second lower wall surface 74. When the wall surfaces 72, 74 are viewed in side elevation, each wall surface 72, 74 has a front portion 76 which extends from the front end 40 and at a constant radius, and a tail portion 78 extending tangentially from the respective front portion 76 to the rear end 42. The first channel 60 is elliptical in cross-section along all points thereof taken transverse to its longitudinal centerline, and the elliptical shape is constant. A distance, which may be equivalent to the semi-major axis of the ellipse, taken from the midpoint of the base wall 68 to each wall surface 72, 74 is less than a diameter of the conduit which is configured to be positioned within the first channel 60. When the first channel 60 is viewed in cross-section along its longitudinal centerline, the first channel 60 mirrors the shape of the portions 76, 78.
The second channel 62 includes opposite first and second side walls 86, 88 which are connected by a base wall 90. A longitudinal centerline extends from the front end of the second channel 62 to the rear end of the second channel 62 through the midpoint of the base wall 90. The longitudinal centerlines of the channels 60, 62 are parallel to each other and the channels 60, 62 are side-by-side. The first side wall 86 terminates in a first lower wall surface 94, and the second side wall 88 terminates in a second lower wall surface 96. When the wall surfaces 94, 96 are viewed in side elevation, each wall surface 94, 96 has a front portion 98 which extends from the front end 40 and at a constant radius, and a tail portion 100 extending tangentially from the respective front portion 98 to the rear end 42. The second channel 62 is elliptical in cross-section along all points thereof taken transverse to its longitudinal centerline, and the elliptical shape is constant. A distance, which may be equivalent to the semi-major axis, taken from the midpoint of the base wall 90 to each wall surface 94, 96 is less than a diameter of the conduit which is configured to be positioned within the second channel 62. As shown, the distance defined by the second channel 62 is greater than the distance defined by the first channel 60. When the second channel 62 is viewed in cross-section along its longitudinal centerline, the second channel 62 mirrors the shape of the portions 98, 100. The minor diameter of the ellipse that forms the second channel 62 is greater than the minor diameter of the ellipse that forms the first channel 60. In the embodiment shown, the first channel 60 is sized to receive a first size of conduit therein, and the second channel 62 is sized to receive a second size of conduit therein which is differently sized than the size of the first conduit. For example, the first channel 60 is sized to receive a ½″ conduit, and the second channel 62 is sized to receive a ¾″ conduit. As another example, the first channel 60 is sized to receive a 1″ conduit, and the second channel 62 is sized to receive a ¾″ conduit. These examples are not intended to be limiting.
End wall surfaces 72, 94 have the same profile and align with each other in the direction transverse to the longitudinal centerlines of the channels 60, 62. When the bender head 22 is placed against a surface 30 in a head down position, the bender head 22 sits level, and such that when the bender head 22 is rolled against the surface 30, the entire length of the wall surfaces 72, 94 contact the surface 30. End wall surfaces 74, 96 may also align with end wall surfaces 72, 94 or may be shorter, as shown. Webbing 108 is provided between the walls 66, 88 and between the front end 40 and the rear end 42. The webbing 108 strengthens the channels 60, 62. Alternatively, the walls 66, 88 may be continuous with each other.
When the conduit is positioned in the first or second channels 60, 62, the center of the conduit is positioned such that a portion of the conduit is always exposed from the channel 60, 62 and a space is provided between the outer profile of the round conduit and the elliptical channel 60, 62. When the conduit is being bent, the elliptical shape allows the conduit to nest within the channel 60, 62 and the side walls 64, 66, 86, 88 provide points of contact with the conduit, instead of the conduit bearing against the base 68, 90 of the channel 60, 62. Since the conduit extends partially out of the channel 60, 62, the conduit is always in contact with the surface 30 against which is it bearing during a head down bending process. As a result, pressure is always applied to the conduit by the surface 30 during a head down bending process for the entire profile during bending. These features results in a round cross-sectional shape of the conduit after bending.
As a result of the structure, the bender head 22 combines two channels 60, 62 with a single ground profile. Both channels 60, 62 maintain their respective center die radius (4.18″ for ½″ EMT conduit for channel 60 and 5.17″ for ¾″ EMT conduit for channel 62). The wall surfaces 72, 94 provide a common ground surface for uniform pressure on the conduit during bending.
The body portion 38 includes markings 114, 116, 118, 120 thereon which indicate bend angles provided on the lower wall surfaces 74, 96 and on the side surfaces 48, 50 to indicate bend angles for the channels 60, 62. The markings 114, 116, 118, 120 provide for accurate head-down and head-up bending, as well as for producing stub-ups, offsets, saddles and back-to-back bends.
The body portion 38 includes a handle mount 122, see
As shown in
The first body part 132 has an open topped, generally U-shaped channel 136 extending downward from an upper surface thereof, and which extends from a front end 138 to a rear end 140, and which longitudinally aligns with the first channel 60 in the body portion 38. The rear end 140 of the first body part 132 is spaced from the front end 40 of the body portion 38. The channel 136 has a base wall 142, and opposite side walls 144, 146 extending from the base wall 142 to an open upper end 148. A rear portion of the base wall 142 and the lower portions of the side walls 144, 146 form a cylindrical shape extending from the rear end thereof 140.
The second body part 134 has an open topped, generally U-shaped channel 150 extending downward from an upper surface thereof, and which extends from a front end 152 of the second body part 134 to a rear end 154 of the second body part 134, and which longitudinally aligns with the second channel 62 in the body portion 38. The rear end 154 of the second body part 134 is spaced from the front end 40 of the body portion 38. The channel 150 has a base wall 156, and opposite side walls 158, 160 extending from the base wall 156 to an open upper end 162. A rear portion of the base wall 156 and the lower portions of the side walls 158, 160 form a cylindrical shape extending from the rear end 154.
As shown in
When the first body part 132 of the hook portion 52 is being used, the conduit is slid through a portion of the first channel 60 in the body portion 38, through the space 164, through the rear end 140 of the channel 136, and then into or through the channel 136. The conduit is parallel to the central spine 130 when inserted into the channels 60, 136. The conduit rests on the base wall 142, and the cylinder formed by the base wall 142 and the lower portions of the side walls 144, 146 provide a stable starting point for the conduit. When the first body part 132 of the hook portion 52 is being used, the conduit is slid through a portion of the second channel 62 in the body portion 38, through the space 166, through the rear end 154 of the channel 150, and then into or through the channel 150. The conduit is parallel to the central spine 130 when inserted into the channels 62, 150. The conduit rests on the base wall 156, and the cylinder formed by the base wall 156 and the lower portions of the side walls 158, 160 provide a stable starting point for the conduit. The channels 136, 150 may have grooves (not shown) in their upper surfaces to assist in gripping the conduits when placed therein. Since the body parts 132, 134 extend outward from the central spine 130, a smaller moment is provided during bending than when both hooks extend from the same side of a single spine.
As shown in
The bottom surface 168 is planar and extends tangentially relative to the front portion 76 of the wall surface 72. The front lower surface 170 is planar and extends at an angle, for example 120 degrees, from the bottom surface 168. The front upper surface 172 is planar and extends at an angle, for example 60 degrees, from the front lower surface 170. The front lower surface 170 and the front upper surface 172 form a V-shape which meet at a front edge 178 which defines part of the front end of the hook portion 52.
In an embodiment, the side surface 176 has a rear surface portion 180 which extends from the rear end 140 and extends between the bottom surface 168 and the top surface 174, and a front surface portion 182 which extends between the front lower surface 170, the front upper surface 172 and a front section of the top surface 174. The rear surface portion 180 is planar. In an embodiment, the front surface portion 182 forms a curved corner, and may curve along lines that emanate from the intersection point 184 between the front lower surface 170 and the front upper surface 172. The front surface portion 182 may curve in a single plane along a radius that is parallel to the flat bottom surface 168. In another embodiment, the front surface portion 182 is formed as a planar chamfer between the front lower surface 170 and the front upper surface 172 and is angled relative to the rear surface portion 180. In another embodiment, the side surface 176 is planar.
The second body part 134 has a bottom surface 186, a front lower surface 188, a front upper surface 190, a top surface 192, and a side surface 194. The bottom surface 186 extends from the rear end 140 to a rear end of the front lower surface 188. The front lower surface 188 extends from the front end of the bottom surface 186 to the front end 152. The front upper surface 190 extends from the upper end of the front lower surface 188 to the front end of the top surface 192. The top surface 192 forms upper ends of the side walls 158, 160 of the channel 150. The top surface 192 forming the upper end of the side wall 160 merges with the central spine 130. The front end 152 of the channel 150 intersects the front upper surface 190 and the open upper end 162 is in the top surface 192.
The bottom surface 186 is planar and extends tangentially relative to the front portion 98 of the wall surface 72. The bottom surfaces 168, 186 fall along the same plane. The front lower surface 188 is planar and extends at an angle, for example 120 degrees, from the bottom surface 186. The front lower surfaces 170, 188 fall along the same plane. The front upper surface 190 is planar and extends at an angle, for example 60 degrees, from the front lower surface 188. The front upper surfaces 172, 190 fall along the same plane. The front lower surface 188 and the front upper surface 190 form a V-shape which meet at a front edge 196 which defines part of the front end of the hook portion 52.
In an embodiment, the side surface 194 has a rear surface portion 198 which extends between the bottom surface 186, the front lower surface 188 and the top surface 192, and a front surface portion 200 which extends between a front section of the bottom surface 186, the front lower surface 188, the front upper surface 190 and a front section of the top surface 192. The rear surface portion 198 is planar. The rear surface portions 180, 198 may be parallel to each other. The front surface portion 200 provides a curved corner of the bender head 22, and curves along radial lines that emanate from the intersection point 202 between the front lower surface 188 and the front upper surface 190. The front surface portion 200 curves in a single plane along a radius that extends from a center point 204. In another embodiment, the front surface portion 200 is formed as a planar chamfer between the front lower surface 188 and the front upper surface 190 and is angled relative to the rear surface portion 198.
The space 164 between the body portion 38 and the first body part 132 includes an entrance area 206 which leads into a main area 208 which is generally circular when view from above the bender head 22. The main area 208 has a radiused portion 210 which forms a front portion and in particular, a front inner corner proximate to the central spine 130. The radiused portion 210 extends along a radial line from a center point 212 within the main area 208. The center point 204 is on the left side of, and forward of, the center point 212 when viewed in
As shown in
In effect, by removing material from the bender head 22 (the removal of the material to form the curved front surface portion 200), the bender head 22 is made more robust than by providing more material with a sharp corner.
While a curved front surface portion 182 is shown and described on the first body part 132, this is for aesthetic reasons. When the conduit bending tool 20 falls under its own weight, the conduit bending tool 20 tends to fall on the curved front surface portion 200. The space 166 may have a front corner radiused portion, like that of radiused portion 210 to form a clockwise moment when the conduit bending tool 20 falls onto the curved front surface portion 182.
Many modifications and other embodiments of the disclosure set forth herein will come to mind to one skilled in the art to which these disclosed embodiments pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the disclosure is not to be limited to the specific embodiments disclosed herein and that modifications and other embodiments are intended to be included within the scope of the disclosure. Moreover, although the foregoing descriptions and the associated drawings describe example embodiments in the context of certain example combinations of elements and/or functions, it should be appreciated that different combinations of elements and/or functions may be provided by alternative embodiments without departing from the scope of the disclosure. In this regard, for example, different combinations of elements and/or functions than those explicitly described above are also contemplated within the scope of the disclosure. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.
While particular embodiments are illustrated in and described with respect to the drawings, it is envisioned that those skilled in the art may devise various modifications without departing from the spirit and scope of the appended claims. It will therefore be appreciated that the scope of the disclosure and the appended claims is not limited to the specific embodiments illustrated in and discussed with respect to the drawings and that modifications and other embodiments are intended to be included within the scope of the disclosure and appended drawings. Moreover, although the foregoing descriptions and the associated drawings describe example embodiments in the context of certain example combinations of elements and/or functions, it should be appreciated that different combinations of elements and/or functions may be provided by alternative embodiments without departing from the scope of the disclosure and the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202321028482 | Apr 2023 | IN | national |
